I think I am understanding you correctly that if I have the flywheel at TDC and the pump at TDC and I use the cam lock when I put it all back together I will NOT have to re-time the injection pump? I will be able to simply re-tension the belt and be all good?
If you do not loosen the injection pump mounting bolts and return the belt to the same tooth, the injection pump timing will be the same before/after.The tube of hylomar is a bad idea for use on a head gasket. No way to spread it evenly and lightly enough. You'll get blobs in the cooling system. On the other hand, the spray cans of hylomar are EXCELLENT for head gaskets. IMO the copper spray is a poor substitute. A very light spray of the hylomar on all four surfaces (head, block, both sides of gasket) eliminates the pesky weeping oil leaks at the drains and the high pressure port to the head between 3 & 4. When I say a very light spray, I mean it. Not enough to make the surface look blue. Just enough to make it look kind of wet.
Just a heads up, that location for your EGT probe is not good. That is a very stagnant area. It renders the reading from the gauge meaningless. You want the probe directly in the exhaust flow and preferably where all 4 runners have come together.The cracks in the precups can either remain the same for a long time or they can grow quickly and cause the insert to crank in half and fall into the cylinder, ruining the engine. If you can find them, then replacing them is a good idea, IMO.
That EGT probe location causes both a low reading and a additional lag to the reading. It is a dead-end location for flow. Imagine placing a thermocouple in a tin can with open end aimed at the flame but to the side of an oxy-acetylene torch vs. having the probe actually in the flame. In other words, your pistons or turbine fins could be melting for a minute or more while the gauge still reads safe. I doubt you ever see near actual peak temps with that probe location.
It looks like Brickwerks in the UK sells the inserts. Pricey, but certainly less than a new head:
If all else fails and you decided to replace the head there is a new cylinderhead on from Topline on ebay now:https://www.ebay.com/itm/1-9-1992-1997-VW-AAZ-NEW-BARE-CYLINDER-HEAD-TURBO-NON-TURBO-DIESEL/274695551628?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649You might be able to swap over the valves. No mine or anyone i know.