I got the engine running this afternoon!

Didn't start first kick, but the old girl tried, just giving a feeble kickback. Considering the mag points were 180° out so the wrong plug was firing I think that was pretty decent of her to try! When I swapped the leads over the engine leapt into life on the first kick!
There was no oil return to the tank for the first minute of tickover. This time I'd remembered to fill the external filter canister with oil before starting the bike so I was expecting a quick return of oil. I stopped the engine and left it for a while. Another start, still no oil return. I wasn't too worried about lack of lubrication while running for a short time because I'd slathered everything with oil as I assembled the engine. Stopped the engine and went indoors for a cuppa. When I started the engine again, lovely clear oil squirting back into the tank!!! Lovely jubbly!
I've been out for a gentle ride around the streets. Engine sounds lovely! The clutch is not freeing up very well despite me adjusting the cable at the gearbox. I didn't take very long over getting the pressure plate right, so I'll take the primary cover off and take more time getting it really good.
My running in motto is 'No slogging, no flogging'.