Just wondering, if when you buy an old Russian/Soviet watch of ebay that seems to be in perfect working condition(Keeps time very well) do you get it serviced right away considering that it probably or may not have been serviced/oiled in a very long time? Or do you wait until you notice that it is not keeping time as well or the power reserve is lower etc.? Or do you wait until it breaks?
I mean even if the rare seller out their says that it has been serviced/cleaned/oiled, you don't know for sure without documentation to prove it.
A watch that seems fully functional could be damaging its mechanism if the oil should have been replaced a long time ago? am I correct?