1974 or 1975 even with that crown.
As you have probably been advised, drop the fork and the steerer might have a date code, more likely if its a '74.
Thick paint could have hidden a date code on the BB shell, the 32 on the chain stay could be a repaint stamp, could have been repainted twice even.
Lots of modifications.
Interesting hole at the end of one seat stay in the brass fill area.
Another Masi incognito.
John Jorgensen
Torrance Ca USA