Originally listed Lode Star slot card from Fort Thompson, SD had a black arrow printed over the original white arrow on the bottom of the reverse. Here's the original card before the black arrow was overprinted.

Here's a link to the originally listed card that's been on the ChipGuide
http://www.themogh.org/cg_showpic2.php?cg=013564

And here's scans of the newly found card