Ok I have a small update for my car, I was incorrect and it does NOT have a M21 but infact is a M20, it has 2 rings on the input shaft
I dug this out of my storage area and it looks to be the matching transmission to the car VIN is 124378N378371 and the trans has stamping numbers 18N37837, also has P8A15 stamped on it
case has a 3925660 casted on the side, tailshaft has 3846429 casted on it, the side cover has a metal tag that I could not make exactly the numbers on it but looks to be 3915077