Marcos Maniacs

For a early Marcos GT with Volvo engine we are searching the donor 
car for the "crown wheel" and the "bevel wheel" in the differential. 

The numbers on these parts are "BTB 654 & BTB 655". The wheels are 
not broken but completely worn out after 275.000 km. It first looked 
as the parts were from MG because you find nearly matching numbers 
(BTB 653 ...) for example in the Moss catalog.

It would be a great help to know the donor differential or the donor 
car, because we don´t believe that these parts were built by MARCOS 
themselves.

CF1700GT