Peter,
I refurbish 'Airhead' boxes for members (16 done to date) but I haven't done an 'Oilhead' box yet.
I have the remains of an 'Oilhead' box that Robmack destroyed that I intend to rebuild one day - it doesn't look too complicated inside (it has a drum selector instead of the two geared cam plates).
If you're really, really stuck I'd take it on, but I would prefer to work on one of my own first.
It might take a while as it would be a new learning curve for me.
Bob.