I found this one:
http://vintagesewingmachineparts.com...2-bobbin-case/
The photo looks like just a standard bobbin case, similar to those for vintage Singers. It could be simply a standard class 15 bobbin case.
I also found these on eBay:
http://cgi.ebay.com/BOBBIN-CASE-Dres...item53e2d894c1
http://cgi.ebay.com/DRESSMAKER-SEWIN...item19b5a6857c
That last listing says, if you're not sure, to contact them.