You two are the reason I have tackled so many old machines. Yes, these techniques work. I've had the best results just using the french polishing method. I focus on one small area at a time. It takes practice to blend. The two fingered method, I swirl 1, 2, 3, and swipe up, seems to be the best. Much like working on other machine bodies, I tend to swipe towards an area that will remain hidden. I hope this helps.