Alan,
Ah, the detent arrangement changed. I did notice the shift arm exited the box to the back on the early models, and then exited the front(without really knowing the reasons why) when they altered the mounting arrangement to clamp around the frame tubes.
By the way, did you know there are three versions of the 1925-26 trans mount? They continued to add metal around the tapped holes, apparently breakages being a fault. Clamping around the frame tubes was the solution, though then the cast alloy clamp is the item often found fractured. Often found replaced by a home-made flat plate clamp of 1/4" steel!
-Doug