I rebuilt an original Remington New Army 44 using Foreign parts. If my experience was what is to be expected you will have a lot of timing and touchy work installing new parts in an old gun. They are not really assembly line made but mostly gunsmith assembled and timed. My Remington was my Grandfathers and had been overloaded splitting the cylinder and left in a box of scrap metal to rust. It will now fire although it is mostly a wall hanger as there is little collector value due to the rework. Replica cylinder ball diameter is smaller than the original which needs to be reemed out to make the gun really accurate. I agree that the internal parts should be cleaned and inspected well before trying to install new parts.