I got the answer.
Ok, uneconomical repair? can get the parts? dont know what to get?
Here's the answer!
first off, Get on the phone to the nearest slot it distributor, usually Sean for me! (Free plug Sean, do i get anything?)
you will need
1 wrench (allen key)
1 9 tooth inline pinion
1 36 (red) sidewinder crown gear for scalex (19mm I think)
then you simply fit them in the usual manner.
If you find the slot it gear will not fit on the rear axle, a peice of sand paper and a dremel will soon get the axle ground down to the correct diameter while still being true and round.
Just dont press the axle onto the sand paper too hard.
Fit the pinion onto the motor, check alignment, then insert axle through bushings and slip the gear on tighten the grub screw with the wrench and glue the wheel back on or get slot it's wheels I recommend Sipa10 which are 20mm in diameter (yes i like big wheels).
and now? the pics of course!