I have been working feebly on a very similar idea, except the "hanger" incorporated directly to the bbl and using a modified original stock, with one of my old Hornet barrels. As pointed out, the short chamber swell makes rigid attachment difficult, but I am convinced that with the correct welding technique it can be done sans scailing the throat or interference with normal bbl removal. Now to find and befriend a good TIG welder...
Steve