your attached pictures are not the best for testing lens performance. Asahi made one of the best 50 mm lens of all times (perhaps besides the Apo Summicron Asph.) the 1:1,4/50 mm SMC-Takumar. The 1:1,8/55 mm and the 1:2/55 mm SMC-Takumar (same construction but rated down to f/2) were also world-class. So I cannot imagine that the 1,7/50 mm SMC-M should be so much worse. Maybe your example is misaligned or a lens is loose. Did somebody tinker with it and reassembled it wrong?