It's been a few years since I messed with them but from what I remember
65 and 80 are similar, 80 has the intercooler and if I remember right has an additional boost pressure sensor on the intercooler pipework. Runs higher boost from a similar turbo but I do believe they have different parts numbers.
100 uses a different more efficient intercooler
80 and 100 use the same injectors I believe, it was the 65 that had smaller ones.
100 uses the VNT turbo
100 uses MAF meter instead of MAP sensor (or was this only the MK3 VNT cars????)
100 all use jr5 gearboxes with hydraulic clutch, later dci 68's also use this setup.
There was talk of different engine internals and there certainly was different parts numbers but I'm unsure of the specs.
It's not something I would attempt without a full doner car as the wiring/ECU etc complications, I'd just swap the lot.
