The MRHA website might be a good place to send a message too. They keep tabs on Milwaukee Road modeling stuff and sometimes sell it.
Did you try Walthers already? They normally carry even the most obscure stuff and can special order what they don\'t have. Plus it\'s good to have Walthers as the middleman in case you get stiffed after sending in money to the small vendor and they go out of business if you go direct.