My collection Leica M3 + summicron 50 rigid bought together in 1962 still remains an L-seal and "B" letter on lens mount. From my knowledge this mean Camera and lens likely never open for service since 1991. Box and all original paper still there. but, the problem is the view finder is blackout and show only focus pad and frame line. Do I need to repair or sell this as a original condition? or How about if I send them to Konton for repair and repaint to black, would be better? Anyone knowing about letter "B" on back lens mount? Thank you so much for all helping.