Wouldn't it be possible to simply swap the bulbs (left to right and vice-versa)?
From what I know, unless your lights were the "sealed" beam type (buong casing is sealed) you the lights are interchangeable.
Meron kasing orientationg ang light reflector sa glass lang ng headlight that directs the beam properly. In fact, the aiming of the light could be manipulated manually through some screws/bolts.