Hey Ed, sounds like your on a mission, great job, fun isnt it?….when I have needed a pocket watch part I have done the same thing, buy a non running watch off ebay. taking a chance as it may not be the right one of even have the part needed BUT for a price usually less than the part itself I have ended up with alot of spare parts for the future, sometime I end up with a movement that is in better shape than the one I am working on (makes it difficult to use as a parts watch) 
Have a great day, William
