The question remains - does it work?

probably but it would be about as fast to hand turn the balance wheel since it only does one stitch for each crank around.. The HCs do 3 stitches for each crank around.

So you'd have to crank really fast to do any real sewing, then.

Is there a regular hand crank setup available for the FW, or do we have to rely on these kinds of work-arounds? I don't think there is any spoked wheel that will fit on a FW, is there?

The FW doesn't have the motor boss on the side of the machine. The Singer 66 & 99 some do and some do not have a motor boss on the side of the machine for the HC to attach... There are other machines that will HC. The Singer 319 will not - the hole does not line up square with the hand wheel. There are some Japanese 15s and some Singer 15s that will HC - again the motor boss has to be on the side and line up square. I'm thinking some people have built up the side on a FW and attached a HC - lot of work. The little window winder might work but it would be a lot of turning to do it. I have a Japanese deluxe type machine that will HC but is isn't much fun.