I have some updates on this situation.
As of May 2020, at least two pieces with the suspect Type 2 stamp have re-appeared on eBay and Etsy under different seller names. The listings now omit the claim that they are Gaillard. Please see the Updates section at the end of this post for more information.
Original post, March 13 2020
There are two virtually identical “Gaillard Paris” stamps that I see on copper pots and pans for sale on Etsy and eBay. They’re hard to tell apart, probably intentionally so. I call them Type 1 and Type 2.
My assessment is that items with the Type 2 stamp may not be genuine Gaillard. Type 1 appears on pieces of consistent 1930s-1940s Gaillard styling and quality; Type 2, by comparison, appears on pieces that range widely in styling, quality, and apparent age. Based on the examples I see, I believe Type 1 is a genuine Gaillard mark but Type 2 is not. TJFRANCE has previously noticed this issue and has posted a strong statement about it on his website (update: he added examples).
I learned to tell the two stamps apart when I noticed that the letters of “Gaillard” and “Paris” are aligned differently in each version. I can show you what I mean with these examples from my collection. (Click the photos to see them close up.)
My opinion: Genuine Gaillard, 1930s-1940s
My opinion: Unknown origin
The Type 2 stamp is often inexpertly applied: it’s mis-struck with doubled letters, and/or so forcefully applied that it deforms the copper or leaves an additional imprint from the frame of the stamp. This amateur technique is another warning flag that the stamp may not have been applied by Gaillard.
The bottom line is, do not be misled by this Type 2 stamp. I do not think it is a real Gaillard mark. If you find a piece of copper with this stamp for sale online, consider it for its innate qualities — a stamp doesn’t change a pan’s thickness or condition or how it will perform for cooking. But do not be misled into thinking that you are buying a collectible Gaillard: It is most likely not genuine and, perhaps most importantly, not worth the inflated Gaillard price.
I speak as one who fell for it: Buyer beware.
Important note: There is a third “Gaillard Paris” stamp with smaller letters that I assess to be genuine. This stamp is smaller overall with narrower letters that are closely set. I believe this stamp represents genuine later-era Gaillard from the 1960s-1980s. Below is a visual comparison of all three stamps.
March 22: Reader Alarash has shared some photos of a poissonière he purchased from the seller in question with the Type 2 stamp. He notes that the pan was stamped in two places, which I have never heard of before. You can also see a square outline around the stamp and distortions in the copper around it, more indications that it’s not a maker’s mark.
March 22: TJFRANCE amended his original statement on this matter with more examples — take a look if you haven’t already seen it.
May 21: Please be aware that some items have been moved from the original seller to other stores on Etsy and eBay. It may be difficult to trace all the items with Type 2 stamps, particularly as it appears that the original seller is moving them between stores. I’m grateful to eagle-eyed readers who have spotted them. As always, my suggestion to buyers is to ask about stamps and require clear photos of them. Reputable sellers should have no problem supporting their listings with straightforward information.