Mark, it can be done just with a little carefull welding etc. Using unworn rear latch, just lay them side by side and is easy to see what needs doing.
Remove raised corner on rear latch and replace with flat piece, refit to door and drill hole, can use self tapping screw.
On rear latch the interior lock knob lever #2 needs to lengthened same as front and hole drilled to accept lock rod, is easier to weld 1st, grind flat and then drill hole. Lever #3 can be trimmed off or left.
Just check things out 1st, its not rocket science and close enough is still workable! regards bill.
OOPS! Just realised this should be in This n That section. sorry!.
AussieBill YYYY Forever Y Block YYYY
Down Under, Australia