Nice one Charlie! Look forward to seeing it; my TII cab was wobbly but fun with a quite manageable 250ish but 421 must be as scary as you say it is! Will be hoot, that stiffened shell will be a real bonus.
What do they weigh as standard? I'll be impressed if it does end up under 1000kg with fuel. Just got my Eunos turbo to 1000kg and its lost basically everything.