Right this is what he is doing. I think.
I have checked his ebay buying history and it shows him purchasing these lights from Germany as LHD for about 130 pound. He then just swaps the red and white bulbs over and hey presto, RHD lights.
I will be ordering some Black in.pro lights and doing likewise very soon.
Watch this space
Good detective work! Let us know how you get on with the bulb swap experiment...