Sandy Koufax Signed Los Angeles Dodgers Jersey. PSAThe Left Arm of God! This gorgeous Los Angeles Dodgers road flannel jersey, produced by Mitchell and Ness as part of their Cooperstown Collection, is signed by one of baseball's all time greats Sandy Koufax! Mitchell and Ness Cooperstown Collection jerseys are the finest quality and official replica models for vintage baseball uniforms. This particular signed version features Koufaxs name and the year 1963 expertly embroidered in blue stitching,