02 diff

For my project 1600-2 ti I need to rebuild the lsd. In the parts catalogue there are two diffs described, a long and thin one and a short stumpy one. I have on the car a long one and in my spares cupboard a short one. The short one obviously does not fit under the car because the mounting points are different. Does anybody have an idea whether the internal parts are interchangeable?

Copy from the Walloth & Nesch catalogue.

Mine is the upper, car is from 1967, spare is as lower picture. Both are racing lsd's, approx 4.1 or 4.4 ratio. Crown wheel is obviously different, how about the rest of the parts?

Early E21 323i Diff's are supposed to fit?