Well this is this project pretty much done. I always wanted to know if it could be done, and as I hadn't seen anyone else do it, I thought I would have a go myself. I went from knowing nothing about the TCB to learning a huge amount over the weeks that I was working on it. Luke was an immense help, I can't thank him enough.
It's not remotely difficult to do. Very little soldering, and all of the components are cheap. The advantages are the customisable sounds, and as all components are separated, if anything fails, it can be replaced, rather than buying a whole new set up as is the case with other aftermarket systems.
It's set up with motor drive and sounds, and main gun sound, you can of course take a look around the Open Panzer site and see the long list of what the TCB firmware can do. The options are pretty much endless, different speed controllers, sound systems, IR battle system etc etc, plus all of the programming options that are available from the on screen display via a USB.
As mentioned previously, I'll do a PDF showing what I did, and why, with a step by step how-to.