Okey doke. Well as I've been dutifully following your advice all the way through this registration process Kev & you've yet to lead me astray, aluminium plates it is.
The front one will be square & the rear's a regular rectangle, (already got a recess in the bodywork for it). I'll contact them tomorrow.
So here it is- the little scrap of paper this has all been about. A fully legit tax disc.

Jason, the guy who did the vehicle inspection yesterday, rang me this morning to say Nice DVLA Lady Michelle was finishing the paperwork as he spoke & I could call in to collect it this afternoon. So as soon as I finished work at 2.30 I headed up the A3 into London again. As I walked into the waiting area he spotted me from his desk, grinned & waved an envelope at me. I could've kissed him when I opened it, (maybe that's why there's a glass screen across the counter). My tax disc, registration number & letter authorising the number plate manufacture. The logbook, (or V5C document as they are now), will be posted to me.
Can't believe it's finally over! We've turned a pile of old scrap into a car & the authorities officially recognise it as a legitimate road going vehicle. Yes, I'm chuffed!
We've still got a lot of work to do -most of the bodywork's only tack welded together & everything's in bare metal. The engine's misfiring & not picking up cleanly when you put your foot down. It's gonna look unfinished for most of the summer ...but now we can legally take it out for a spin. How cool is that!
As I said, it ain't over yet, lots still to do, but to all you guys who've leant a hand, given advice, donated parts etc, (you know who you are), a big sloppy kiss on the nose to every one of you. Couldn't have done it without you.

Manky Monkey Motors
Mankymobile
Registration Q--- UGF.