My house was built in 1950. We took off the old crane sink and are trying to attach a new pedestle sink. The pipe in the wall is a dark metal and the inner diameter is about 1.5 inch. I do not think it is copper. We cannot attach a standard 1.5 inch chrome drain pipe kit from Lowes because the compression fitting is too big. The 1.25 inch fitting is too small.

The metal pipe is threaded on the outside, but somewhat corroded, but still sound. What do we do?