Full text of the article with lots of photos and links is here.
I've pasted some of the relevant info below:
TERMS
BARRACUDA
Sellers often use this homophonous spelling of Baracuta in the titles of similar jackets from other brands. I’ve not seen it officially used in any brand’s marketing, but it’s widespread enough to be useful in searches.
BASEBALL JACKET, BOMBER, GOLF JACKET
If you search these terms, you’ll see some Harringtons. But you’ll also see a lot of things that are not Harringtons, as you might for the terms windbreaker, wind cheater, spring jacket, and light jacket. I’m including this here to either save you trouble or offer additional options.
BUTTON COLLAR
The collar is perhaps the defining characteristic of this style of jacket. Rather than being angled downward, the collar point is perpendicular to the band and designed to be upturned and closed. Traditionally, a two button closure is used. It’s a functional detail designed to keep the wearer dry and warm.
BUTTON CUFF
While many Harringtons have an elastic cuff, some, like the the Baracuta G4, have a button cuff and tabs at the hem. Personally, I prefer the button look, as it’s a bit more streamlined. I don’t actually expect to get caught in a rainy windstorm while I’m wearing mine.
ELASTIC CUFF
Most Harrington jackets, including the G9, have an elastic cuff and hem, in keeping with its original purpose to keep out wind and water. The cuffs and hem are a prime spot for wear and stains, so double check any jacket you find for fraying, distortion, and discoloration, and be sure you’re satisfied with their condition.
FLAP POCKET
Like the collar, the flap pocket is a standard feature. Generally, the pocket flap is slightly pointed and uses a single button closure. The button here is often missing, and you might miss it if the flap is open. Of course, sometimes there’s a zipper and no flap. To me it really doesn’t make a difference. Purists may disagree.
HARRINGTON
This term delivers on what we’re looking for, and has no brand association. According to every little blog post about the history of the Harrington, the term itself comes from a character on Peyton Place who wore a similar jacket. For what it’s worth, I could find no evidence of the jacket on the series. Instead, here’s a generic title screen of no value to anyone.
LINED
The traditional Baracuta has a tartan lining throughout the body and a polyester lining in the sleeves. A plaid lining is common, though not universal. Lined jackets are, of course, warmer, and they tend to be a bit better quality overall.
MOD
Mod is a popular term sellers use to describe Harrington jackets. It refers to the British subculture of the late 1950s and 1960s in which similar jackets were popular, particularly those from Baracuta, Ben Sherman and Fred Perry. Baracuta released an ad campaign celebrating the style.
RAGLAN
A raglan sleeve extends from the cuff to the collar of the jacket, with an angled seam from underarm on up. Most Harrington jackets, including the Baracuta G9 and G4, have a raglan sleeve. It results in a certain fit at the shoulder, but it creates a kind of looseness, too. It fits the jacket’s original purpose.
REVERSIBLE
Reversible Harrington’s exist, and they can be sorta fun to have around. It also means, though, no functional interior pockets. Often, one side is solid and the other a tartan.
SCALLOPED
Often the back of a Harrington jacket, as on the Baracuta G9, will feature a second layer of fabric, similar to that of a classic wool cape coat. It’s designed to keep you warm and keep the water offer. Often, the bottom hem will be scalloped. I’m not sure why, to be honest, but it looks like it helps managed the effects of wind and rain while adding a cape layer for warmth.
TALON
A brand of zipper. The presence of a talon zipper on a jacket often, though not exclusively, dates the jacket to the 1970s or earlier. By the 1990s, most jackets used zippers made by YKK.
TARTAN
A tartan is a the woven plaid pattern representing a Scottish clan. Some are older and more prominent than others. Baracuta famously uses the Fraser tartan for the lining of their jacket. Many other brands use a Tartan as well, though of a different clan or invented from scratch.
TWO-WAY ZIPPER
A two-way zipper has two opposing zipper pulls. One closes the jacket as it goes up and opens as it goes down. The other opens as it goes up and closes as it goes down. That enables the jacket to be worn with varying levels of closure, which is lovely for days of varied weather or after a large meal. The original Baracuta uses a two-way zipper.
UNLINED
This is pretty self-explanatory. From experience I can tell you that it’s a bit more like a shirt than a jacket. But on nights when it’s warm but you’re still trying to layer something, an unlined Harrington is the way to go; it’s hard to find a lighter option. And because unlined Harringtons are not much different from a shirt, it’s easy and affordable to have them slimmed up.
WOOL
A wool Harrington is hard to come by, and I’m tempted to say they’re not worth the effort. If you’re going after a short wool jacket, then you can find something a bit more flattering than the oft poofy Harrington. The price for wool tends to be higher, and vintage ones I’ve handled often pill.
BRANDS
BARACUTA
The brand that started it all and today the standard for quality. These run about $400 new. Vintage Made-in-England versions generally go for $75 to $200. The Van Heusen off-shoot of the 70s and 80s, which are made in Taiwan, Hong Kong, or Malyasia, go for less, and to me seem marked up for the brand name compared to comparable pieces. They are still perfectly fine jackets, though.
FIELD AND STREAM
I’ve handled quite a few of these, and find them altogether fine. The liner and shell are sturdy, the zipper is heavy, and they are often fairly priced on the second-hand market. Gordon & Ferguson was/is a private label for the store Field and Stream, so it’s worth searching both. They are made overseas, and most appear to date from the 90s and 80s.
LAND’S END
Another jacket without a sexy brand or history but nevertheless a darn nice jacket. I’ve handled a few of these, and rate them highly. They are lined, sturdy, and generally affordable. I have seen a few, too, that are made in the USA.
LONDON FOG
London Fog makes a nice unlined Harrington jacket. They come in a variety of colors, and many are made in the USA. For whatever reason, though, they’re often marked up at thrift stores and online. While a mark-up might only be $12 instead of $6, just be aware that their are comparable options with less thrift-cachet.
IZOD-LACOSTE
In the days before Izod polos were on the JC Penney clearance rack and Lacoste polos were on Russell Westbrook, Izod-Lacoste made a nice jacket. It features the trademark Crocodile, and some feature a vibrant plaid lining of red, green, and yellow. There’s something fun about having the famous logo on a vintage piece. They’re worth the average price of $30-$45. I date most from the 80s.
SEARS
Sears made a lot of jackets under a lot of sub brands: Oakbrook, Kings Road, Sears Men’s Store, Sportswear, and so on. They’re all fine, and if you find one in your size then snag it. The resale prices, though, are often a bit high due to perceived age. They may be from the 60s or 70s, but that doesn’t make them worth $60+.
OTHER BRANDS
What about Fred Perry and Ben Sherman? They made a name with the mod crowd, but I’m yet to find a true vintage Fred Perry or Ben Sherman Harrington jacket in person or anywhere on the internet.
Other familiar brands made Harringtons, but they’re not common enough to warrant their own write-up. LL Bean and Woolrich have made quality versions and with domestic manufacturing. Catalina, CalCraft, Towncraft, Maine Guide, and McGregor versions exist as well. My personal favorite came from Scorecard: For Men of Action.
TIPS FOR SHOPPING
Unlike, say, a nice denim jacket or a leather jacket, you’re likely to find a vintage Harrington within a few thrift store visits, assuming you’re a common size and not too picky about color and other details.
At thrift stores, vintage Harrington jackets range between $5 and $15. The higher end are those that are lined or perhaps deadstock, and those from oft-marked up brands like Lacoste and L.L. Bean.
On eBay, vintage Harrington jackets range from $20 to $60. I consider $35 to be a fair price for a lined Harrington in the style and color that you want, and $20 to be a fair high-end price for an unlined version.
Prices trend higher on Etsy, but you may find peace of mind in the quality of photos and additional details often found on listings there.
When shopping, be on the lookout for common points of wear and failure.
The buttons on the collar and pockets are often missing or very loose.
Ribbing at cuffs and hems is often frayed or stretched.
The seams within hand pockets may be ripped, so be sure to feel around.
On unlined jackets, the discoloration at the neck can be as bad as on a dress shirt.
All that said, they’re a durable and accessible garment, and minor wear will not greatly reduce the look or longevity of the piece.