Improved Compact Flat Subtractor

While trying to figure out the optimal steering mechanism for my Sherman I realised my compact flat subtractor can be made slightly differently. This design doesn't require 28 tooth gear 46372 which some of you said was hard to get, but instead uses 28 tooth gear 65413 from newer enclosed differential. It also doesn't need to connect the differential frames at the front of the frame which means it can use either type of differential an old one like here or the new enclosed one. The trade off for it is the connection between differentials being outside of the frame which shifts the motor position by one stud.