Lucky you!! try this URL: www.singerco.com/support/machine-serial-numbers
the serial number should be on the right front base.
have fun with your 201 -- it's supposed to be "the best machine singer ever made.
Joann
ps --- curious - what did you pay? my hubby got a filthy, rusty electric singer 15 for $5 at an auction when nobody would bid on it (with another machine and lots of parts). I cleaned it up, spent $10 on cords, $20 at sewing shop, and have a wonderful old (same age as me) machine.