Well, I thought I had seen it all when it comes to the 1968 Topps 3-D baseball card test issue but, as evidenced by a discussion over at Net54 recently, another bit off oddness has turned up:
Odd Clemente items are nothing new here but I am scratching my head on this bad boy. This style of pennant does not appear in any of the guides I have(and I have a few) but the Buccos mascot dates to the 1960-67 period, according to Chris Creamer's sportslogos.net. The version here is missing the crossed bats below the head but looks pretty close otherwise.
So the logo dates to just before 1968 and the pennant seems ideally suited for a 3-D card to be displayed. Could this actually be a type of an internal Topps presentation? Is it a piece created after the fact by a third party?
If another team could be found with a 3-D card attached, I would lean in the direction of it being a Topps prototype. Curiouser and curiouser.