I had decided to use my Dymo label maker, but I have not yet found it. While in the local Dollar General store, I noticed a pack of two Sharpie fine point permanent markers. One is Gold, one is Silver. $3 spent, and I now can read the keys again. Both colors work fine. I used silver on the letter keys and gold on the spacebar (not that I needed to put the word "space" on it, but I wanted to try the gold marker).
Not the neatest job, labeling it by hand, but it's labelled and easy to read. That is all that matters. So far it's holding up real well, and if it does wear off, it will only take a few seconds to re-do it.
Problem solved, and I'd highly recommend it if you need to re label black keys. It's real easy to see, in fact it's better than the original (because I made the letters BIG)! [I had 14 keys without any letters anymore, and it was getting hard to type].
I'M HAPPY :)
BTW: I just wrote my name and address on the back of my black cellphone with one of these markers, in case I lose the phone! These are handy markers!