Cox Chopper V1 restoration

Hi all,

first of all I need help from you : does someone could told me the exact measurements of the worm gear on the hexagonal wheels axle for the Chopper ?
The one I'm restoring is missing this part.
I could make tests on différents gear from my other toys but it will be more efficient to ask you directly the measurements, the forum is there for that  
I need (in inches) the outer diameter + the inner diameter (between the teeth) + the all width + the width of the left round side + the width of the right round side + the number of teeth

Just notice the worm gear of the Chopper is spécific of that model. The Buggy or Sandblaster or Matador/Adam are différents.

Thanks for your help.

Will post pictures right soon.

Franck.