Really? Wow, so it is plausible. Fiddlesticks I guess, but I'm still happy to have them. I wish I could know for certain though.
One thing of note...
There was a Gretsch kit for sale within the last couple of years that had a wrap that was never in any catalog (it looked a table top from a 1950's diner table). I think the consensus was that maybe they made the kit as a super special custom order for someone, or Gretsch was thinking about offering the wrap, and wanted to make a sample kit to see how it looked. In any case, it's entirely plausible that your wrap is original.