My El Cortez chip (below) has a small number next to the dollar sign on the left. It appears to be S74 or 574. Does anyone else have this chip? Does it have a number on it?

If my scan isn't clear enough, there's one on eBay (not my auction) in the link below and it doesn't have a number. My thanks to anyone who can help.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=63750&item=6175431236&rd=1