I am refinishing the veneer sole in my 78 h33. Stripping the old varnish/polyurethane or what ever it was, was an easy task. I can't seen to get a couple of old stains out though. The stains must be from a spill during an oil change and have been there for a long time. Does anyone have a suggestion for getting them out or making them less noticable. They appear deep enough that sanding is not an option. I've tried TSP already and it didn't make any difference.