Can anyone tell me where I can get MDS Engine parts either in the US or in Australia?

I am looking for the carby retainer and some "o" ring kits for MDS 48's fitted with the C2 Carbys.

I've had them on order at my local hobby shop in Oz (where I bought the engines from) for over a year and figure that they are never going to eventuate so I fugure that while I am here in the US I might as well try to source them from here.
Thanks

Steve