Don't cross-post: ask your question, wait for answers, then continue the thread. Don't ask the same thing multiple times in multiple posts. One thread per subject per user.
That said, the card the French square comes from sells for about $2 if complete and unused. I'd guess this square is worth a few cents, assuming you even find a buyer. The British one might be the same, don't know for sure.
The British one is listed in my 1986 Michel catalogue, most recent reference I have for postal stationery. It was issued in 1921, and lists for 3 Deutschmarks which I believe was about 75 US cents at the time, but that's for an entire card, so as stated above, negligible value.
Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Stamp Community assumes no liability for errors. Copyright 2005 - 2026 Stamp Community Family - All rights reserved worldwide. Use of any images or content on this website without prior written permission of Stamp Community or the original lender is strictly prohibited. Privacy Policy / Terms of UseAdvertise Here