A quick update to this thread for those interested in the minutia of these lenses. In response to my lens hood inquiry, mdarnton very generously sent me a W.Komura 35/3.5 lens that had some significant issues, along with a hood that did not, and was thus perfect for my W.Acall (thanks again!).
On a lark, I decided to pull the Komura apart and see what was going on. Before I even turned a screw, I noticed some differences between it and the Acall. The former has no click-stops in the aperture, but the latter does. The scalloping on the barrel is different, with the Acall having wider radiused gaps between the raised portions, while the Komura has more tightly-spaced sections with sharp 90deg transitions between them. The ring securing the optical block to the barrel is also different.
Once apart, I cleaned everything and replaced some missing and damaged screws, which resolved the problems with one notable exception: separation between two of the elements. I have no intention of trying to fix that, and a quick test on my X-E1 suggests it won't make much difference in any case (even straight into the light, there's no visible effect). What was surprising about this phase of the operation, however, was that I discovered that the lens is in fact a Double Gauss arrangement, apparently six elements in four groups, not the Tessar variant (4/3) that I had expected (and I believe I had read somewhere, but I can't recall the source). This helps to explain the excellent performance of these lenses. I haven't pulled the Acall apart to see if it shares this optical arrangement, but I strongly suspect it does.
