Part of the reason that you can't find another one like it is because there are two different light fixtures there. The one attached to the ceiling is a pan fixture from around the late teens into the 30's. (try google image - pan fixture)
It would have had round coloured lamps in each of the holders because there are no shade holders. It looks to me like someone took the centre piece out, this was usually a brass tassel & ran a wire down to put the other fixture through. I can't really say when the second one is from, I don't see that style here very often, I think it may have been a more US style of light. GG