Hey Roger...

OK, one thing at a time... The diff housing... This can be replaced very cheaply, and probably someone here has the original plastic ring that goes around it that they could donate, as they are often discarded in favour of a metal diff. If not, then the metal replacement will work for you and is $7 anyway.

The bigfoot is what we call a 'marder clone', in other words a clone of the famous FG model buggy, the Marder, and the smartech copy is widely hailed as a good effort compared to many other marder clones. So good, that it in turn was cloned (badly) by another company Sheng Qi.

This means that a lot of (but not all) original FG parts will fit, and while sometimes slightly more costly, are worth getting when the opportunity arises.

There's a very good online store, we all use it for our HPI Baja stuff, and now they've started doing FG items too, it's called DDM (Daves Discount Motors), and the web address is davesmotors.com . I think is what you need at the moment... http://www.davesmotors.com/store/product2300.html

anything else we can help with right now? Nice to see you made the switch to large scale, they're very satisfying to run compared to nitros.