I just fitted some new lock barrels to my '63 yesterday . There was nothing on the packaging that said they had to go on one side or the other so I just threw them in any-which-way and they work just fine . The barrels (The bit you push) look identical either side .
Just make sure that the key operates in the handle before you re-fit them to the doors , mine were a bit sensitive to the internal spring seating properly so best to check first . Also the door handles are mounted with two short bolts that have a special security type head (A bit like an elongated Allen head) that either needs the right tool to undo or , like mine , is so mangled from someone else's bodging that most of them will need drilling out .
Good luck
