There now appear to be THREE variations of the grey Castle Host card from Trump's Castle in Atlantic City, NJ.

One card has no "SM" after "Castle Host" on the front, here's a link to the scans on the ChipGuide
http://www.themogh.org/cg_showpic2.php?cg=018770

The other two cards both have "SM" after "Castle Host" on the front but one has the registration mark after the castle picture in the Trump's Castle logo on the front. Here's a link to the scans of that cards on the ChipGuide
http://www.themogh.org/cg_showpic2.php?cg=018771

The new found card has the registration mark moved down after the word "Castle" in the Trump's Castle logo.
Here's a scan of the new found card