Glen,
Thank you. Nice to know they are out there and the timeframe they were used. With all the of the postmarks, did the post office count them as valid postage? On your example there is 21c total postage. Was that the postal rate to NYC in 1931?
Anyway, these look like they were made as a fundraiser for the Guatemala Red Cross. I'll treat them in my album like I do with Christmas seals. Unless I hear from others that they had other uses.
Thanks again.
Tim