The only potenitial issue might be the break angle off the back of the bridge.

My first guitar, a Harmony H76, had one and it worked just fine. My guess is that the top of the casino is thick enough to support a B7/B70/B700 just fine but if was mine, I might consider a B3 that didn't have to be screwed down to the top. Here's a picture of Lennon playing it before Paul had it restrung sinister style: McCartney's Casino has a B7 on it as well. Previously, Epiphone had their own branded Bigsby (didn't say Bigsby on it so I've always wondered if it was a knockoff). Epiphone had a special run of Casinos with Bigsbys that I thought looked fantastic.