Thanks!!
First coat chassis black went on last night:
In the meantime at home, I drilled a 3 mm thick plate for the brakebooster.
I will weld it in on the firewall, and make my own swingpedal.
A lot of drilling to get a hole of almost 2,5"
I must have a flat surface to mount the booster, so I have to look how I manage that.
Can't remember exactly how the firewall looks like at that place, I'm getting old, I think...