I own a Mamiya SUPER and I have looked thru the user manual to see if GN401 will fit to this body.
But, there is nothing there about this winder.
This winder is a very old model. One thing you can try .... is to go Peninsular shopping center ( P&G , CamX or Camera workshop ). Go look at the display Cabinet and see if there is any GN401 winder there, then ask the shop keeper if he allows you to try fitting to a SUPER.
good luck
Billy