If I have to share my mind on this, I was given a pocket watch belonging to my great-great grandfather from the beginning of the 1900. The cost of having it fixed was not reasonable in my opinion, plus I'm not a pocket watch person so it would end up being a huge expense without any return in real life.
I ended up having a crystal fitted on it and now sits in a dome display case above my writing desk just as a piece of my family history.
If I were in you I would make a quick pro-cons list in my head seeing if you'll get benefit from having it a working state. If you do not wear it, nor intend to, and would be a dead-expense, just keep it as a memory of your grandfather in its original state.
