Awesome build, just started tearing down a '80 CB750F myself. Looking forward to see what you do with your bike, I'll be trying some similar things after cleaning and restoring all the mechanical and electrical.
As far as cleaning the bike, I have never worked on a bike in my life, but the Clymer manual has made disassembling the engine a breeze, highly recommend if you want to learn the insides-and-outs of the DOHC. After reading around the web I decided to try out mineral spirits to clean the engine gunk, seems like a lot of people have had success doing such. Thougts on this anybody? I'll post updates to my thread as soon as I get to it (hopefully tomorrow). Cheers!