Yes, I recall Harrah's Sports Casino ... in the same building which became Bill's, as you noted.
Unfortunately, I don't have any pictures. My recollection ...

Harrah's moved their poker room to the Harrah's Sports Casino, and I played there on a few trips to Tahoe.
It consisted of a few (maybe 5-6) BJ tables, plus 1 each Roulette and Craps tables, I think.
The poker room was maybe 8-10 tables, nice friendly games.
The bar in back had a sports theme and TV monitors for games.
Even a small stage where local bands played live music.
Some regular slots, plus 50 or so of the old chrome Jennings slot machines (mechanical only, not electro-mechanical).

Good luck on your book.