I have something to share...
Yesterday I bought a 221 from a friend I met at guild. I couldn't find the serial number, as I was looking for a metal tag at the bottom of the pillar. Silly me! It was on the bottom of the machine! She is in great condition. All decals are intact. After checking the serial number chart, I find she is a sister to your new machine, MrsBoats. I was surprised to find the belt is leather! She needs a cleaning and some exercise. She has been sitting on a shelf for 20 years.