WOW!!! What a stopwatch! I really like the caseback as well. Sorry to say that from my understanding, Waltham watches are only worth a few hundered. Well, at least most of them anyway. For your particular one, I can not say for sure; but, for all the ones I have seen, even in the 1800s, the selling price has only been a few hudered.
BTW, how did you come across this watch? It is STUNNING! Congrats!