Ah, I think I see what you mean now.
"just remove the screws designed only to restrict the camera to accept Polaroid backs only."
I want to use the back so I can attach a focussing hood for macro work, but I then need to switch back to the polaroid back to take the shot, so removing and adding screws is not really an option for switching between the normal back and the focussing hood.
Have a look at the last comment here:
http://photo.net/medium-format-photography-forum/00HS8i"Since I had two polaroid backs, I could save myself 100euros by buying new Madapter for mamiya universal if I sacrified two locking pieces of polaroid back. I read about it extensively on the internet, but thought modification is more demanding. Well, it is not, there are just 4 accesible screws to unscrew and there you go."