We have faith in you Ron, you can pull it off, we have done some over the years just like that and WORSE, wish I had taken pictures back then of "before & after".appears to be water damage, neglect, like left in a basement after the fire departemnt put out the fire UPSTAIRS......find it some time later......gun left submerged does a different rusting pattern on and ALL over the surface, almost like 'layers'............only concern to me would be just "how deep" and where the serious pitting is on the cylinder, looks like its over the fat, meaty part ...and YOU know how well 'sandblasting' (glass? ) can do wonders in these areas :wink:
(glad YOU have the parts,,, last one sent back to the factory, they could NOT, would NOT, "fix" a loose extractor/ejector rod.......) :roll: they said they "no longer had the parts...." and would replace the gun with an SP 101...........(at dealers cost) 8)
Happy New Year !! .......... we await the "work in progress"