I just purchased a 1915 International Alto Saxophone made in Elkhart Indiana. It looks very much like a Conn, and I was wondering if anyone has heard of it before.
1915 is the patent date, not the production date. It could well be a Conn "stencil" horn. Stencil horns were horns produced for merchandisers to market under their own brands. There's not a lot else to say unless there are some pictures that show identifying features.