Brinky,
I asked myself the same question a little while ago. From my reading, the RHD units are no longer available. I did find one mob in the UK that would convert new LHD units to RHD units, but they needed your RHD units to do this.
I compared my old RHD light with a new LHD light that I have and the only difference I can see it the pattern on the glass. I thought that if I could strip the glass from the old light I could put it back in the new light.
Old glass in held in place because the edge of the reflector has been folded over it. There is a small rubber gasket behind the glass. New glass looks like it is just held in by silicon or something similar.
I managed to successfully remove the glass from my two RHD lights without any damage. Just have to be patient and not be heavy handed. Being glass they clean up very well.
Have not tried to remove the glass from a new unit yet but I imagine it will be just a matter of slicing out the silicone. Won't know if the edges of the old and new glass similar enough to allow the old glass to be put back in until I actually try. In my own mind I think it will work and I suspect I will buy another new light one day and give it a go.
Just need someone else to confirm that the pattern on the glass is indeed the only difference.
Word of warning, the pattern on the inside of the old glass has some very sharp edges. (Don't ask me how I know.....)
Sorry about the quality, but you can see how
I have folded back the edge of the reflector.
You can see the rubber seal that sits in
behind the glass
