Unfortunately the stripped wire was the negative wire and the 47 year old multi-meter no longer gives an accurate reading in volts. (9 volts reads at about 10.5 volts because the needle moved when it tried to go backwards). Oh well. At least the Boss FS-6 still works and I can still use the multi-meter to test polarity - LOL. I probably won't replace it. I will just through out batteries that don't work (Much cheaper).
I went looking for cheap volt meters and it appears you can get the needle type for $24 or so. It is probably wise to get a digital considering this story. I am assuming all digital types will survive something like this but then again I have not owned every one that exists so maybe I am wrong.