Well, small update for your entertainment; ~4 hours work later and we have this to show for my efforts:
Now the front bodyposts will stick up through the hood (bonnet to us Brits) instead of the windscreen.
I have also enlisted the Candyman to make me some tranny mounts- basically gonna be like 4 legs under the tranny (stock mounting points), which will in turn be mounted to a plate which goes above the center skid, mounted to the bottom of either chassis plate (where the little plastic standoffs are currently). If you understood that you're doing well...
In the mean time, it doesn look like I can use the stock lipo tray or electronics plate either- the motor will stick up too high; blasted traxxas designed the new tranny in such a way that the spur is offset too much to one side to have the tranny mounted low down within the rails, so the only option is to mount it higher for clearence. No biggie- wont be too long and I'll this thing up & running and ready for a test run :)