Far from being a Marlin expert, I would say that they are the same actions. My Mod 75 looks identical to my Mod 60. However, the similarities may be reserved for specific model years.
My "go to" parts guy tells me there have been several changes in the actions of the Mod 60 family over the years. When I need parts from him, he's sure to ask me specific info about the particluar rifle I'm servicing.
Brownells and Numrich Arms are good places to start looking. You can talk with the technicians at Brownell for specific questions.
Hope this helps.
EVOC ONE