If you have to go inside the engine, please be aware there are differences between the F and K models in the top end parts, heads, cams, and, even differences between different year F models. Early F had a basically K-like head and cam setup in lobe centers and valve angles, later ones, different, larger valve'd head, different valve angles, piston domes, and completely different camshaft basics, and that stuff DOESN'T interchange.

Those bikes are the best of the early "single cammer" Honda 750's, I feel. The later ones are fairly fast, and run really great when tuned correctly.

I used to have one of those and yes they run forever it seems but what I thought was aftermarket greyish black sidecover were indeed stock. You would have thought they would have been burgundy like the bike. I had the factory four into one but don't remember it having that end section as it seem to sweep up a little and have a cone type end. It's one of the only bikes I have owned where if it tips over you need a crane lo lift it back up . Cool find hope it goes all well.