Thanks Rob and Mav,
Can you get a nice close up shot? If I can't borrow an original I might have to make up a blank to get cast so it would be good to get it right. Brass casting is not cheap, either you have an expensive mold made or cast in sand, which is expensive in time as the mould has to be remade for every pour and there is much more cleaning up of the part.
I was going to do my own casting using white metal but I would much prefer brass.