Hi Sixnut - great progress, as always! I like your new front airdam too, looks like a useful downforce aid with that splitter. Without the front bumper it looks just like a Giocattolo
(are you going to use the bumper, or run it without?)
I'm sure you've received all the advice you need on fuel tanks, but one other possibility that I can't help mentioning is Lancia Stratos fuel tanks. These are obviously available from current kit manufacturers like Hawk (who I believe acquired the Transformer model) and others.
Anyway, back to the point - the Stratos used two slim inverted cone tanks either side of the rear bulkhead, just forward of the (transverse) V6 engine. I'm guessing that with a longer overall wheelbase than the Stratos you might have enough room behind the seats to squeeze them in?
Obviously they would need to be protected from side impact, but a comprehensive roll cage would do that.
Or, if there is enough space behind the seats across the width of the car, an X1-9 fuel tank? Or has that already been suggested?
I'm with Alfa 302 - Orange - that outrageous orange-red used on Lamborghini Miuras (my Barracuda was painted a similar colour, was actually a Skoda shade!)
A 1970's car deserves a "high impact" colour. Plus there is an inherent safety value in hi-vis!
(just don't get caught speeding... very obvious