[Arran]

When it comes to the cloth covered power cords, if they are not frayed, and are flexible, and if I can bend one without hearing any cracking noises, I reuse them. It's only 120 volts, and there isn't any real amperage being drawn through them, maybe 1.5 amps on a big set, cord was rated for 10 amps when new. If you want a more suitable plug for it keep your eyes open in the second hand stores, or in a junk plie, for a cap style plug on something. I've ended up with them from random pieces of junk, appliances, and old lamps, they sold them in hardware stores for years, probably well into the 1980s.
As for cleaning the dial it really depends on the year, the 1936-38 ones had a water soluble ink on them, on a 1932 model I'm not sure. The one on my Philco 60L was NOT water soluble, neither was the dial on the model 96, I always test them in a spot where it it will not be seen, like the first line on the low end of the dial, around where the eyelets are, a little water on a q tip, if some of it comes off you can always draw it back in again with a fine tip marking pen.
Regards
Arran