Hi..
Not sure if this will duplicate since i tried to post it previously..
Looks like Dick and I are both recommending the same place...
I got some parts for my 73 pinto 4 speed at
https://www.taylor-race.comThe fellow there builds a lot of 4 and 5 speed racing transmissions based on the german 4 and 5 speed top loaders with the integral shifters.
You might want to call Taylor and pick his brain.. when i was there I got the idea that he builds all sorts of gearboxes.. be may have a used box in good shape, or recommend a source for a good used box.
I also had a 72 capri and it did not have the integral shifter like the pinto 4 speed, it had a side mounted external shifter.