I understand all that, in terms of whether TCDB wants to list it. There are just always comments questioning this type of stuff (see the 1991 Wild Card Doug Allen discussion for a recent example) and it is usually the same 3-4 members. A lot of people in the hobby have done a whole lot more work on this stuff than most realize and to have "high ranking" forums members instantly dismiss unusual/odd/confusing items is doing the hobby a great disservice and seems out of line with the goal of TCDB.
And true Re: Allender's list, which is why I won't say for certain how this card was distributed - I simply don't know and the promo pack mentioned is a possibility. If you look at the Peace Dove lucite card, it is manufactured exactly like the card the OP posted. Not similarly (and not like those old "3D" 1991 UD cards that father was making), it is the same process used for the Pro Set lucite cards, which, I might add, are a handful when you consider the NFL ones produced in tiny numbers. If you are familiar with those, you'd see that they, too, use the exact same production method as this and the dove.
Owner and creator of JunkWaxGems, online source for unlisted error, variation and oddball info from the junk wax era.