That Mamiya is from the 6x9 press camera (I have one in a Copal shutter.) Usually you remove the front and rear lens half’s and transplant them in a Copal 0 shutter. I may be seeing wrong but that looks like a Seiko shutter, and I was surprised the aperture scale matched the lens. Was the setup or that lens original? Or is it a well done transplant?
Indeed the Mamiya lens is for the Press/Super/Universal series of cameras. Copal and Seiko #0 shutters are interchangeable, though the #1 shutters aren't.
This shutter is from a Fujinon 150mm f/6.3 lens. The aperture scale doesn't really match - the aperture begins to close down only at f/11.5. It will have to be re-calibrated. The shutter works properly.
The Mamiya 50mm is supposed to be a Biogon design and is very sharp.