A couple other covers:
The cowboy cover is a favorite but only lists 23 Fremont. The 30-strike cover (which I have yet to see a full book and I think it's a feature?) has a listed location as 25 Fremont, as is the same on the 20-strike feature matchbook you shared, and both have the "Las Vegas Turf Club" advertised which may have been a separate area within the Las Vegas Club specifically for betting horses? The stories behind this "stuff" are as interesting as the "stuff" itself.
Hope you're enjoying your summer!
Eric