Raider11,
Thanks from me too. I saw this and did it to my boil kettle, and love it. Easy to see into, less crevices for crud, and lighter to boot.
It did take a while, and I was sweating about grinding too deeply, but it worked out well. Haven't shined it up and probably won't.
I used the cut out with 3 SS washers soldered on for the lid, but need to find a better one, it is easy to drop the lid into the kettle, and with a water heater element in there, that's not such a good idea...