i am trying to replace a cartridge for a moen single handle faucet for my shower stahl. when i removed the knob and plate to get to the cartridge area i noticed that the pipe was slightly bent inward ...
I don't think there is a way to get it out without opening the wall at least a little bit, but you could use a base plate on the new fixture that could cover an opening. Moen isn't the highest quality and this sort of thing seems to happen allot. I would suggest going with a higher quality large base plate
Plumbing Supply replacement I know Kolhler makes some really nice shower fixtures that may meet your need.