Like Jeffs Ive also had about 1/2 dozen chopped cards with the bio backs. I say chopped because most were not cut well making me think they were cut along time ago. They were all from the same seller on eBay quite a few years ago.
I havent paid attention to the uncut sheets Ive seen, dont know if they were all blank backed or if some had printing.
Here is the only handcut bio back I have now...
