If you look at the Leica LTM copy page, you'll find an entry on my Reid III. Look on the Internet and you'll find more information on them which is pretty fascinating. Essentially they are a copy of the Leica IIIb and not the IIIc which apparently takes longer to manufacture. As for the build, yes they do feel different and are 20gms heavier than the Leica. Oddly, Reid&Sigrist started manufacture in the late '40s but the camera at that time was already ten years old. The M mount was not that far away and so the camera was doomed from the start. Certainly a very nice camera to handle because of what it represents in the context of UK manufacturing and its later demise through absence of innovation.