Does anyone have knowledge of any good sites that contain lens schematics, perhaps diagrams for repair? I am trying to repair these older 35mm lenses and it's starting to become a pain trying to fix them with trial and error, although it has been working. I just feel I could do this more efficiently with some reference sheets or something. Please let me know. Thanks Oh, specifically I am working on (as of now), an older Tamron 28mm f2.8 lens. One of the old m42 mounts.