they werent issued in packs, just part of the fleer bankruptcy cards, therefore not in the opg. usu7ally backdoor print plates like this sell for about half of regular print plates, sometimes less.
there's a chinese seller on ebay that sells many Fleer printing plates. I bought a Rik Smits one and noticed it didn't have any verification of authenticity so I got a bit suspicious on it. Best case scenario they're real and from the bankruptcy sale (I like o go with that theory), otherwise they're imitations....