The start-up the other day was mostly to check all systems
before it goes on the dyno Monday morning.
The guy who runs it has the appropiate name "Speedy".
He knows his stuff. particularly old stuff; he runs a turbo-charged Norton.
One thing we checked was if the vacuum piston in the CV carb
actually did lift all the way up at WOT.
I would have been surprised if it didn't
what with the blower and all, but here's one nerdy video to show it:
CLICK( probably won't win me a most-seen-YouTube-video prize...ha ha
Took the heads off to check things.
basically it all good:
absolutely no trace of damage to the fine new copper gaskets...PHEW !
No damage to the piston tops.
One little problem:

...slight valve/head interference.
Fortunately the heads are made of marsmallowium.
AURGH ! You might recall that I
DID check for clearance before
engine assembly.
The problem is that the diameter of the bolt-holes in the heads a quite considerably larger
than the diameter of the bolts , so the head can move about.
I really should have made some dowels ( is that the term ?) going
through the head / gasket / cylinder, to keep them in position.
Any way, I removed enough material so it won't happen again

There was a slight sign of bolt-lubrication 'sweating' around the bolt-holes
its way into between the gasket and the head/cylinder
so this time I painted the gaskets , both sides, with zinc paint
before assembly, as suggested by some good folks here.

This also gave me an oppotunity to position the gaskets perfecrly on the head
while the paint was wet. I let it dry for a while and the gaskets were thereby 'glued' to the heads.
I could then turn them around and position the heads on the cylinders
WITH the gaskets under them in the proper position.
Getting ready for the dyno-test.
Wish me luck
and have a brilliant weekend ya' all !