Found a new variation for this set. Similar to the Up Close and Personal Silver Signature cards which were printed on base cards (black bottom border), the team checklist cards between 328 and 355 could also have the black bar on the back. I have found the Brewers card showing Pat Listach and Roger Clemens to both have it.
1994 Upper Deck Collector's Choice - [Base] - Silver Signature #333 - Pat Listach
Courtesy of COMC.com
Clemens is attached to show the color difference on consecutive cards.