I unstuck a 401a. I used strips of old t-shirts, q-tips and cotton balls that I soaked with 90% rubbing alcohol from Walmart, sewing machine oil, denatured alcohol from Home Depot (pretty much the same as the rubbing alcohol, but more expensive). I also used kerosene (unscented lamp oil from Walmart). You soak the fiber and rub it on the yucky places until the brown gunk comes off. I used the strips to go under things and "see-sawed" the strip until I had to change to another strip. A pair of hemostats is helpful to get the strips, or cotton balls into the tight places. It took a while, but it's my go-to machine now. (Don't get the alcohol on that red lever, it will dissolve the paint.) I used various solvents at various times so I'm not sure which is best. I think the alcohol works best, though. (Don't use alcohol on a Black Machine, it will dissolve the finish.)
If you'll look at some of archaic arcane posts here and on
youtube, you'll find great tutorials. I think AndyTube did a series on the 401a on youtube as well. Andy tube is very detailed, Archaic arcane moves a little faster. Both do excellent tutes.
bkay