CB 650 appears to be the last of an undying breed. Went well into the '80'a as far as I can tell s a SOHC.
If you look for "honda cb triple clamps" on ebay you finda bazzillion of 650 parts compared to a few other models. I assume other parts would have similar search results.
There is a thread with a CX-500 tank on a 750, and there is a couple pics of two different bikes with that. It looks cool, might be shaped a bit more like a 350f. The procedure was to change the frame tank mount location.