Apparently they haven't made this line of trumpets (supertone band-master made in Elkhart) since the early 30s so it's from then or before. From the very little I could find online about even the company it seems they made good quality student trumpets for Sears from the 1910s(some forums said 1880s)-1930s and then stopped exsiting. I've found some pics online from a 1933 model that looks almost exactly like mine and has an extremely similar case so that's my best guess.
I'm so excited ^.^ I've been trying to get a trumpet for a long time now, but I had no idea id get one that's nearly 90 years old, in the original case, and in great shape for only $145. From a really cool lady too so I was happy to help out that local shop.
Liberty Park Antique Emporium in Salt Lake City ifanyone's every around.
They have some cool shit.