I was thinking the same about all W123 prop shafts being the same until I saw this =>
I've asked around and apparently this two UJ design was not only used on the long wheel base W123s but also on some of the early W123 sedans and coupes.
I've been told there's a list in the FSM somewhere - I'm still looking for it!
As for the validity of the data posted by LutzTD I guess it is pretty good - as he's a top chap! But I have no way of verifying any of it.
I can say the same about 200T over on BW (the other link I posted) he seems to know his onions too! I can verify the measurement I made for the front length of my prop shaft (on the BW thread) that's off of a W123.130 chassis...