My head with the same valve adjuster issue looked surprisingly "good" upon disassembly, valve guide wear aside.
I expected serious seat recession, or heavy valve tuliping but could only see some heavy burning.
Not an easy thing to measure either, e.g., compared to the other head. I guess it's a sum of a number of small faults, rather than one glaring one--best left to a real machinist, not an amateur like me.
"You should do at least one thing every day that scares you." – Kurt Caselli