Model M60, all in rolled gold, was introduced in 1965. The model was one of the luxury models in the M series, and a successor to the 520NN, so to speak. The Model 60 was redesigned in 1970. M60 was similar in appearance to M100, which was in all solid gold, with a few differences: M100's surface was all guilloché, while M60's was striped along its entire length. 

M60 was redesigned in 1970.