Mod: Claas Dominator 108SL Advanced
Great mod and thank you!

These appear to be the controls I have worked out:

Press Space = Handbrake.
Press & hold ?/ = Clutch.
Whilst pressing and holding ?/ press 1 or 2 or 3 for forward gears.
Whilst pressing and holding ?/ press 4 for reverse gear.
Press and hold V = Header down.
Press and hold Y = Header up.

To harvest (in order):
Press X = Unfold harvester.
Press B = Start thresher.
Press numpad 7 twice = Rev it up full.
Press and hold }] = Hydrostat up (moves faster).
Press and hold ~# = Hydrostat down (moves slower).

I hope this helps anyone that needs a brief guide.