I can see now that the LBS made some more, really annoying errors..

I went there beforehand to talk to the mechanics and I made sure they (claimed to) having experience on threaded forks.
Well, the fork is over-tightened; presumably because even so, there still isn't enough thread left for the locking nut to safely tighten to the steerer - there's only about 4 mm max of thread connected and it's an aluminum nut. I will not be riding this bike one meter. And these forks cost upwards of 125 $ - if there ever is one available, that is.

The 'mechanics' also made a couple of very bad scratches on the frame (it's a full chrome steel frame so that takes some effort) - the scratches, about 6 of them, catch my fingernail really hard, so they have to be more than just light surface marks.

I'm very angry at the guys and they ruined my weekend (and probably most of the summer too)...

They also destroyed one of the frame decal stickers (one letter was ripped in two) and replacements need to be custom made.

They also failed to file the inner edges of the steerer after cutting it, so a stem will not fit at all (I tried) - there are edges there from the pipe cutter.

I will call their manager on monday. I would really appreciate if there is a professional out here - I need a pro evaluation of the damage done and
what would be a reasonable settlement.

The too short steerer could be 'fixed' by switching to a lower stack height headset, but the frame damage is not possible to repair, or so I think.
It's a full chrome Coppi, approx. '95 and never assembled before. I paid 320 euros for the frame+fork, both NOS.