You always run into the X factor on scope repairs.
I repair mainly No,32 scopes, Mk.1,2 and 3 and have most of the parts but you always get the one that bubba tried to fix himself or bought as is.
You would not believe what crap you get in for repairs and unless you specialize in a few makes, the parts are impossible to get.
Most current mfrs, just send you a new scope and be done with it.
All the stuff I work on is 80 to 120 years and many have been played with by owners and remember that a lot of the older threads are proprietary and there are no commercial taps and dies available for them.
It is a fun time but satisfying when you get an old girl back on the range for another 80 years.
Lenses are the hard thing to get now and a good glass lens will cost you more than the price of a scope nowadays, unless you order them by the thousand.