There's still the issue of the motors not being mounted level, and I need to swap in a replacement UBEC (currently using an Adafruit PowerBoost board to power the Raspberry Pi) but at least I don't have to order in any replacement parts!
Speaking of which, the NFC reader I ordered back in September has finally arrived... Unfortunately its probably a little to late for me to do anything useful with it.
So with this minor panic over its back to the more general case of 'running out of time' panic! I've got some soldering to do these next few evenings, sort out the motor mounts, work out how to connect the line following sensor to this new chassis, improve the code and various other things!