Regarding the frame and motor to title, that was extremely common in those days to title the serial on the motor. I had a 76 cb550 that was that way. If you do a search online you will find others that way as well. I planned to just register the bike and go on with my life the way it was. I ended up selling it to move onto a 76 cb750 though.

My vote is for making it custom. I'm putting cbr 600 f2 forks, wheels, swingarm, suspension and brakes on mine. Parts are super easy to find, and cheap. You are lucky with your bike not having an oil tank, that's my biggest obstacle!

I'm sure whatever you decide, it will be a cool bike. I love the old hondas!