Up Grades on Stroker-Suggestions

Choosing form over function, you have a problem right there.

Yep I understand that an Airgap will proform better as it is newer technology, the STR-12 is old school but they obviously worked.

TCE in OZ for the converter, if you choose to get locally. But will be $$$$
http://www.tceconverters.com.au/home.shtml
Maybe talk to Camtech http://www.camtechcams.com.au for a new cam.
Even with post charges, getting a converter from someone like PTC or Edge Converters in the USA will be cheaper, but if there is a problem with the stall speed then it will cost you $$$ to send it back for adjustment.

Thanks for the links. The cost of ordering one from the US is a lot cheaper and you are right the cost of getting it addjusted is the down side.