From what I can see, there were quite a few competing brands, once upon a time. I have Casco ads from 1947 and '48, and at least one had a Dremel ad on an adjacent page; they were head-to-head back then. There were also similar tools from Handee, Dumore, Desco, Rolson (British?), Crafty (Sears brand), Warner, Dresco (NOT the same as Desco, above), Williams, Hobbi-Carve, and Whiz Tool. All of these were competing directly against Strader, Foredom, Butler, an unknown brand sold through Bachman's supply, Craftsman/Companion (Sears, Roebuck & Co.), Downey, Flex-O-Shaft, Holland Hardware, Stow, and a variety of other flexible-shaft machines. At least some companies made both flex-shaft and direct-drive tools in this category. I don't know how much name-recognition Dremel had in the late '40s; some of these tools were being offered by 1938, but WW II pretty much reshuffled the deck as far as what companies and products survived.