Good pics.. There are no fault with bearing in fronthouse (aluminium bearing), the marks are honing marks to fit the crankshaft, a little sloppy bearing are nothing to be worried so long the crank case compression are good, castor oil will help to keep tight against air leakage in crank case. I doubt the engine are a ABC engine as i can see the engine are a old "Iron" engine since the pic are showing the steel sleeve and cast iron piston. Use pure castor oil between 20% and 25% in fuel (syntetic oil will kill your engine in a short time). There are the FAI fuel available, it has 20% castor oil and 80% methanol to run your Fox engine.

Hope we see your engine are running in Youtube after you has fixed your engine