This saw was advertised on the local CL and looked good enough to warrant a 30 minute drive to check it out. The owner apparently bought out a closed small engine shop and has been selling them a little at a time. Told me he pitched all the plastic case saws but kept the metal ones. In addition to the Sears, he also had 2 Wright saws there (models B520 and GS2520).
Mike Acres site is down, but it appears this is a Roper saw of between 70 and 80 cc's. Has a decomp on it and you need it to get it to crank over. It is sporting a 21" bar and a good chain.
If I have time tomorrow afternoon, I think I will see if I can get it to crank.