Door, trunk and ign lock sets

sounds like i can match doors and ign but not the trunk unless i modify another door lock to fit back there. Is there a guide on fitting the 66 and later locks to an early car?

Why not leave the trunk key separate from the door/ignition key?

@slantsixdan has posted info on this and there are some threads concerning this mod of retrofitting the 66-later door locks to the earlier doors