[Zeke]

Depends on the level of restoration you want. Lot's of old radio guys are not wood guys and yet do pretty well with Old English Scratch Cover. That can be made at home with some BLO and some tint.

I would first pull the base together with clamps and see how it will glue up, and then glue it. I would use colored epoxy for any voids rather than bondo, but bondo can be tinted brown. Just don't use the red or blue catalyst unless it compliments your tinting method. There is no rot in the damage that I can see.

On the enameled machine itself, I would wax it. You can use black shoe polish if you wish on areas that are not stenciled. A cleaner/wax will take out the minor scratches.

0000 steel wool for chrome but vacuum well, don't blow and use a magnet to pull out stray strands. Use a tissue between the magnet and the surfaces so you don't scratch and you can see what you are getting out, if any.

Get the manual and oil all the oiling points. I have a similar model and the underside is fascinating. There are a couple dozen oiling points. Use quality light weight oil meant for delicate machines. 3 in 1 has a good rep if you don't go to the trouble of buying Singer oil. Whatever you use for fine machinery should be clear, no tint from sulphur.