What a difference a better tool makes! I visited a machinist tool shop and came a way with an air operated die grinder, a disk mandrel and a selection of sanding and cleaning disks. The tool runs at 20,000 RPM and does a real nice job of cutting through surface rust. So far I have only used the polishing disks, I really don't want to take off metal unless I can measure the results.
What I really went there fore is a machinists straight edge, so that I could check the bed and platten for straightness. They did not have those in stock and I got talking with a real helpful guy behind the counter and I came away with this real fine tool. Now I'll have to rent a better air compressor for a few days.