Neal, thanks for the tip. I searched ProX's web site and their tech catalogue has a thrust washer

Size: 25 x 42 x 1.0
Order Code: 03W.25421.0

But there is none with 25x45x1.5.

I will probably again have to ask the workshop for the measurements, maybe they got it wrong or maybe I misunderstood it.
If you find anything different in old post (or whereever) I'd be glad if you could let me know.

Maybe someone else with crankcase re-building can indicate which size is correct?

Gebhard.