I purchased this watch some time ago, and thought I would post it so the serial number can be recorded. 34900200.
Appears to be a nice original watch in a nice original case marked Cased and Timed by Elgin National Watch Company.
Nice watch. Interestingly it seems original except for a replacement bow. This is a very common problem with this case type and I don't really know why. You can look for photos of similar watches to see what the bow should look like and search eBay for one or maybe Dave at Dave's Watchparts might have one.