Slightly depressing update this time.
With the dash, the ICE, the geometry, the head, alternator, carb and filter installed it was time for a road test.
Backed off the drive way after the engine warming up quickly (nice to have a bypass back) onto the hard standing behind the garage. Slipped into "D" pulled forward and gave some gas... Only to be greeted by the engine spinning up with no motion!
It would seem the HG failing a couple of months back allowed water to ingress into the transmission and contaminate the clutch plates, breaking down the fibre on them and essentially screwing the box royally!
So after finishing the interior, the sounds, the geometry, the paint and the engine, the gearbox crapped out.
I'm now in the awkward situation of hunting for either a good (but cheap) 2nd hand box, getting a full rebuild on the transmission or taking this as opportunity to delve into 16v.
Arse!
Updates to come when something is figured out.