Hartge 17" classic 2 piece, where to get new outside rims?

[parsonsgfys]

Hello chaps,
I've managed to crack one of the alloys on my E36 - had an argument with a curb, and the curb won. They are Hartge 17" classics split rim. Does anyone know where I can pick up a new outer rim? Or perhaps there might be a company that can fix them? I've found a few places that sell the whole wheel but they are a bit on the pricey side. Any advice would be greatly appreciated.
Thanks.
Nick