well, in my opinion, no matter what you decide to do, you have already ruined the frame by drilling it for the engine mount.
if you sell it, you may not get as much money for it as you think.
If it were my bike, the first thing i'd do is clean up the wiring, relocate the cdi to a hidden spot and install a better, longer spark plug wire.
I'd build a custom exhaust, and a custom gas tank for it...then i'd keep it.
it's a pretty cool looking bike, but i personally would have done things differently on it if I were building it.
Just my opinion.