I love that bag!! I may have to try that for the latest 401 in the household.
I picked up a 401A this weekend. Yes, the really bad seized up one I said I left at the estate sale. The one that had been in a house fire. I went back for it because I thought I might be able to salvage the motor for another machine. Then DH challenged me to try to restore this one.
It's working. The machine is at about 95%. I have one stuck pin for the raising and lowering of the throat plate. That's it. It went from having the horizontal shaft not turn, the piggy snout seized up, the throat plate not moving, the slide plate not moving to everything turning, but no zig zagging motion in a matter of an hour. About 2 hours later, the zig zag was back.
The next morning (today) everything was freed up but the throat plate. The throat plate lever only moves the left side pin at the moment, and the other one is soaking in fluid film. We heated it, no go so far. DH has used cold in the past to free things, so we're trying that too. Hopefully tomorrow it will be free. Meanwhile, the machine has been completely cleaned and reassembled. It looks really good. Except for the slide plate and the throat plate, all of the corrosion is gone.
These are extremely resilient machines. If they could do a stretch stitch and FMQ they'd be the ultimate machine.
I did learn something interesting while messing with this machine. Not all of the black cams will fit on it. Some of the have a smaller space where the locating pin is, and the cam can't seat completely. The cams I have as spares came from a 648, so it may be worth looking carefully at which ones a person buys when getting them from ebay etc. *wanders off to go take some pics in case someone wants to see the difference*