My 51 was bought new by a farmer in Indiana and when it wasn't working it lived in a barn. It stayed on that farm until 1989 when the old farmer died and a neighbor bought it, doing a cosmetic rehab...without touching the drivetrain or anything on the underside. When I got it there was 63 years worth of an oil saturated dirt mud encapsulating the frame and all attachments. When it was good and hot that first August of ownership, I started spraying diesel on the encapsulated frame. After 3 or 4 days of spraying daily with a pump up sprayer I donned coveralls, goggles and started cleaning with a gasket scraper, a couple screwdrivers and wire brushes. As Steve said, under the crud was near new black paint. After a couple days of gouging, scraping and brushing I sprayed the newly liberated frame and everything else that was now clean with straight Purple Power and then started washing with a 120v pressure washer. Frame came out looking too good to mess with. That was 4 years ago and it's still original with no extra effort beyond the occasional car wash spray.
Good Luck,
RonR
