Just for info, too, here's a quick and updated rundown of all the everknown Demonstration Cartridges:
1) Copy used in the old black and white image with a system displaying the RCA logo on a TV, as correctly noted by TLD1985.
2) Copy that, along with the "Diagnostic Cartridge", was added by Andrew Krieg based on unknown evidence to all of the online collector lists sometime in 1997. Whereabouts of both items currently unknown.
3) Copy owned by "Dan" "McIntyre", who per his own account had it displayed at PC2K, and also had with his copy of Bingo at PC2K1. Likely a different copy than the one above, as whoever had that also seems to have had the "Diagnostic" which "Dan" is not known to have had. Then again, it could be the same as the above, if "Dan" was the source of info that got it added to the checklists. This copy vanished along with "Dan", sadly.
4) Loose(?) copy that slydc kindly posted an old image of the front label of several pages back. This is possibly either of the above-mentioned copies. Nothing further known of the copy in the image.
5) Boxed and possibly complete copy that Tom Keiser trashfound in Philly, along with many other Studio II games and other RCA memorabilia, and which he described as having a unique white box. Believed to have been lost in Hurricane Sandy and the resulting aftermath.
6) Loose copy that turned up just now in the possession for 40 years of a family in North Dakota, having been purchased along with a system and several common games from a hardware store in rural Cavalier, North Dakota that closed in 1977. This copy also provided our first clear images of the backside. This copy is now safe in worthy collector hands
7) Boxed copy that a very lucky gentleman obtained in December among a lot for an Ebay BIN of $29. Copy had previously been among the belongings of a former RCA dealer that were sold at an estate sale. Current owner generously shared good images of it among us, and I'm confident that it too is in good hands
So, just seven possible copies ever known at all, 3 (or even possibly 4) of which may be the same copy, and only two of which, one boxed and one loose, are still known to exist.