Dorfler and Jurka was a German saxophone maker who at times made horns as a contractor for Julius Keilwerth and made horns based on Keilwerth designs to sell under their own name. To add to the confusion, D&J stenciled out saxophones to many of the same companies to which Keilwerth did the same, and names on the stencils were shared for the Keilwerth-based stencils and the D&J stencils. And since the D&J horns were based on Keilwerths, it can be VERY hard to tell the difference!
Incredibly, D&J even built a stencil for SML (Strasser-Marigaux-Lemaire) at one point.
Just another example of the weird, wacky and entangled history of German saxophone manufacturers.
For the most comprehensive history of Dorfler & Jurka anywhere, including photographic proof of the D&J SML stencil, check out the Dorfler & Jurka History Page on Helen’s Sax Blog.