As you predicted, the guy in the shop ran a cylindrical gauge down the barrel from the chamber and showed a steady, clear 7.62mm throughout.
Seems like the barrel of the Zastava is in good condition!!
Still not sure I want to spend so much on a used gun, mind...
For €75 more I can get a brand new Marlin!!
You cannot wake someone who is pretending to sleep. Stop pretending. Wake up.
Freedom: Please enjoy responsibly.