IT'S ALIVE!
It was a hard day, but finished all the tasks: changed the glowplugs (easy when the head is on your lap), cleaned all the carbon buildups from the pistons and valves, checked all the tappets, and put the head on the engine. The only pic I took yesterday:

Took some time, as my buddy was working a bit on his mk2 TDI and wasn't able to help me.
When it was all done my pal said: "you'll need another battery to start her up, unbolt one of the inyectors and let it crank till you take the air out". Nah. I sat inside the car and started cranking it... all of suddenly, it made some trakatraka*pooof and saw some black smoke comming out the exhaust.. little pause, then some more cranking and it started perfectly.
It sounded perfect! We were both amazed. I parked it outside the garage and let it iddling for some time, to check everything was ok.
As the valves aren't its own, I came back home (60 miles) avoiding the highway, using local roads, and it was great fun. No overheating, no odd noises, no vibrations.
I have my GTD back, and I'm happy again.