Most of those were just standard dropouts filled with brass. I would drill a few holes in the filler and then use a hacksaw for the rough removal. Then clean up with a file. The filler has no structural properties. My bet that it's a 80's Schwinn.
__________________
I'm not one for fawning over bicycles, but I do believe that our bikes communicate with us, and what this bike is saying is, "You're an idiot." BikeSnobNYC