My two cents worth, all the breather covers i've seen clearly have a gloss painted finish, silvery grey color, which appears (to me) very different than the aluminum color on cases. The broken set of sandcast cases (accompanying 232) came with early engine parts (including sandcast cam chain tensioner and a painted gloss silver grey breather cover.) The sandcast cam tensioner appears to have an aluminum finish covering the metal, appearing same as cases. The one early finned oil cover I've seen, with no internal webbing, *appeared* to have a painted surface, the coating of the paint was thick, not as bright aluminum color, compared to the thin painted coating seen on the cases. I'm not sure what to say about the head and the cylinder block. My personal belief on early heads/cyls, based on not having the best early examples to look at, these parts were painted same as cases, but i would hazard to say there was possibly a thicker layer of paint on the upper surface of top fin of head, next to the cam cover. Later (not sandcast, perhaps later K0 and certainly K1) heads/cyls, my observation,used another type of coating, a very thick coating that seemed "rubberized," would peel, could actually pull off, "stretchy," in consistency and when subjected to high pressure cold be peeled off in loose areas, half to 1 inch at a time. I'm also going to hazard the guess, as production numbers advanced, the finishes used on these engines was also a more refined and automated process. What i am saying, is the early and very early bikes engine finishes may have been applied differently, using different application methods and materials, compared to later bikes, even perhaps, the later sandcasts.... Deciding what an original engine finish may have looked like for a particular Evin range, particularly in early production might be a challenge to say, finishes were "exactly" like this.....? I would not be surprised to hear varying observations.
