MAN Traktor Forum - Treffpunkt für Traktoren Freunde

I have a MAN C 40 A tractor here in Finland (serial number 8-500136/97).
I am looking for following parts:
1. Zylinderkopfdichtung - Head gasket. The engine is burning oil (cylinder 4) and I need to take the top off to fix it.
2. Radnabe/horn - Stearing wheel hub/horn
3. Schaltknauf - Gear shifting knob

Do you know if there is a way to find these parts?
Best regards

Mikael