The next big issue to resolve was crankcase pressure. I tried various plumbing methods, with breathers, catch cans and PCV systems.
From heavily smoking breathers and stinking up the garage I finally put some of it back into the carb. But while it improved, there’s still too much pressure blowing oil out the valley pan and elsewhere.
So after much research, tonight I'm going to install this vacuum pump along with a neat Wagner adjustable PCV valve and a new Elite catch can / separator. I’m hopeful this is the solution.