We visit family in New Hampshire each Christmas, and one of our favorite things to do is explore antique and junk shops. A new one opened up since last year, and we found the attached below. The owners had given up on it-- it's frozen solid; nothing moves. He was happy to give it up for $15 and I couldn't walk away without it. I know nothing about this brand. I think the serial number is 547245. I haven't started trying to loosen it up yet. But I've got all the various brands of junk to do so.
Here's a number I found on underneath that initially I thought might be the serial number:
But then elsewhere I read that the serial number is on the stitch regulator plate:
Not easy to see in this photo, but the numbers go up the left hand side (or top) of the above plate. They're 547245.