Remember mid December the tilted adapterplate discovery was a sign to take a break and sharpen the saw? Now I took it all out of the car again and had the adapterplate corrected. Think they mixed up with the Volvo 240 in which the motor is a bit at an angle. But that is a different one. Either way, it is fixed now.
After finding the correct orientation with a loose Siemens motor flange, Mischa TIG welded the old holes. That allows us to drill new holes in the correct position.
Adapterplate modified. Reason/trigger for the tilt appeared to be interference of a guide pin and motor bolt. The latter has now been drilled all the way through instead of countersunk. After fixing the guide pin the adapterplate was installed back on the car.
Next the flywheel and after cleaning it the carefully aligned clutch and pressure plate.
And finally after some power lifting (the jacks did better than me) the M400 gearbox is back on and everything back in place.