I think I got things backwards but could not help myself, I bought the barrel first.
The seller advertised a Mauser barrel, octagon to round, integral rib & front ramp,
slider rear sight, in 7.6S (30-06?) calibre. On the rib is the following "Waffenfabrik
AG Oberndorf AM Neckar".
It turned out to be small mauser thread but I'm still pleased. The seller also sent an
invoice from 1946 when the barrel was removed from from the original rifle and rebarreled
by Johnson Automatics Mfg. Co. Providence R.I. and has been in his closet ever since.
The original # on the gun was 82896 (1921?)should anyone happen upon it.
Now what to do with it - any comments / suggestions will be appreciated. --- John