Im currently researching my 1000OTS coupe, which was converted to 124/1300 power by PBS, and I was lucky enough to talk to one of thier guys, who actually remembers what was done(years ago!) durring the conversion.
He stated, besides the re-bore,and the gear drive, that they usually changed the camshaft to an "A6" grind. Also, they probably balanced the crankshaft, and changed the rod bolts, but not much else for street use.
He also asked me if my car had thier double a-arm front suspension, but mine still has the leaf spring.
I was surprised at the information they had for a 43 year old car with a 40 year old conversion!
I think Im going to keep this car as a124/1300 for the time, at least until the original motor drops itself onto my doorstep!
Chris