Thank you for the kind words.
Anistasia, It is about as simple as unbolting the motor and bolting on the hand crank. This is a reproduction hand crank. You just need a Singer machine that has a spoked handwheel. I have seen a tutorial about notching a solid handwheel, but it is pretty involved and the results are iffy IMHO.
vmaniqui, I have been polishing them up with a cordless (much slower speed than corded) Dremel with the felt buffing wheel and jewelers rouge and following up with wadding polish for years and have had great results. The faceplate on the 66 was bad so I took a chance on it to see what would happen if I used a brass brush. It is now going to be what I do on a lot of them if they are rusty or really bad. As long as you can polish it up with a dremel or other buffing wheel after to clean up the small scratches it leaves behind you may want to try it on something that is in bad shape to see what it does. The brush can get in the fine detail really well and it takes off the first layer of rust really quickly. Buffing wheels can also leave behind minute scratches that look like swirl marks after you wax a car. On small areas they are not as noticeable, but on something like a slideplate, you will notice it.
I hope this answers your questions. If not you can always message me.
~G~