Repairing cast iron fire surround

Recently I bought a decorative cast-iron fire surround to replace a missing one
in my 1880s house (and not incidentally hide some horrible modern maroon tiles
that were put on next to the old ones.) It had one break that had been fixed
once before, to judge by the welding marks at the back.  I'm trying to get a
ballpark figure for fixing it once again. 

 The piece is only 3 inches wide and the break very clean--put the pieces
together and 3 inches away you can't see the fracture.  What sort of artisan
would be most likely to do a good job on this?
zemedelec