Yep Peterson tanks have all the good bits, 3 segments inside the top entry and spiral plates, a middle section with mor spirals and baffles then the bottom section which ita drawn from.
I've had a tank spun up preveiously and replicated the Peterson baffle/ divider but the ammount of stuffing around and spinning cost it is easier to buy one!
The inner turret idea has been done before to a few prod cars doing the rounds. And a few other category cars which don't allow fire wall bars. It's pretty nessisary on any circuit serious nissan, the front ends suck badly.
I do have an over hung tilton box you could utilise Neil
you just need to keep the pivot points of the pedals within 75mm of original if my memory serves me right?