The Swiss company, Waltham International SA, has the rights to market Waltham watches outside of the U.S. (and perhaps Canada) and it has continued existance. It is recognized as producing quality watches.
However, the company that made your Waltham is the one that owns the rights to the use of the Waltham watch name in the U.S. Their watches aren't as highly regarded.
Pocket watches similar to the OP's are still available from dealers on the web. They have identical (pseudo railroad) dials except for the brand name and use the currently available ETA Unitas 6497 movements.
I think that OP is short for "Original Poster", i.e., the person who started the thread. However, I could be wrong, as with anything pertaining to the internet and computers (OK, other stuff too!). I suppose it could also be a typo for OOPS!
Thank you for the information, fellows. Y'all have given me a great starting point.
I was mainly concerned about if it would cost more to have the watch serviced than what's it worth. It has absolutely no sentimental value. I might purchase some tools and do a little tinkering myself given that the watch appears to be fairly common.