a quick thought on ‘recently serviced’... i’m a clock guy, but i imagine this applies to watches as well. over time, my understanding of what constitutes each part of servicing a movement... and my ability to execute properly... continues to evolve.
for example, i have a large regulator i’ve serviced multiple times... mostly because it would run for months and months but with a small pendulum arc despite my best efforts and ‘servicing’.. and then it would go through a phase of stopping. i only today... after several years... realized that the piece of rod i used originally to replace a broken crutch rod had too much flex in it and was robbing power from the train. after double-checking everything else (bushings, slop, no bent pivots, acceptable smoothness when powering by hand with verge removed, and so on) i replaced the crutch rod with something stiffer... and now have a larger pendulum arc and can tell it has more power and will run more reliably.
moral of the story is that unless you know for sure who serviced it and how thoroughly, you just don’t know... and should probably go through every new acquisition yourself (or farm out to someone you trust) to make sure everything is up to the expected standards... and even then....
btw... this time around i hand-turned new great wheel bushings, front and back, on my sherline... skills acquired more recently. that didn’t fix the pendulum arc issue, but did remove one more potential issue from the possible culprits list. when you’ve removed or dealt w all potential issues, it‘s probably ok to consider it serviced.
again, without knowing who did what, how well, and how recently , you can’t really trust that it’s been ‘serviced’.
