As I recall (I was much younger then), the original intention was to restore SP 6402 to operation, and in black widow paint. The work was being done by retired SP employees. All of the ply-metal side panels were shot, so they came off in anticipation of being replaced. Then Dennis Dougherty (sp?) came along and decided that there would be no non-steam projects. He ran off the work force and the locomotive was left bare. Sometime later, the locomotive was prepped, primered and put on display as a "visible" locomotive, basically making the best of a bad situation.