Dems - I wondered if it, using car parlance, has a full service history?
Proof of such can sometimes enhance the value as well.
Appreciate that insuring the watch is a must however on the subject of "worth" itself, it's all relative if we're talking real worth.
The watch will undoubtedly have many great stories to tell. (is it a talking watch? ) and the fact that, if I've assumed correctly, your Dad has passed it on to you is a magnificent gesture and speaks volumes of your relationship together without knowing anything.
Enjoy it, for it will bring more pleasure than all the greenbacks in the world. (sort of)
J