It works!!
Many thanks for the great help!!
I restarted the work from field one.
- Identification of the DR 3 wiring -> did it correct the first time
- Identification of the PRS7 wiring -> did it correct the first time
- Connected them together according the provided wiring (many thanks to Mongoose) -> same as I did it based on other diagram
And it did run!
It seems to me that the PRS7 contacts were probably corroded. At least after many switching attempts it started to work on all three positions.
What I previously identified (direction change) was the change between Normal and Park.
The motor did never run on Fast….