The serial number should show up in the ISMACS.net database as a 201. It's a great machine. You can download the manual at
ISMACS. The stitch length numbers are worn off or faded. (I've seen that area repainted on a youtube video, but lost the address when my computer died.) It has a drop in bobbin, as you described. It loads differently than later drop in bobbins, so check the manual.
It doesn't have a belt, it is direct drive. It's a straight stitch machine only. It's the quietest, smoothest machine Singer ever made. It's often referred to as the Rolls Royce of Singers. It also looks like the cabinet is in good condition.
It has nothing to do with a featherweight. The featherweight is a 221 or 222. This is neither. The model number is 201-2. The -2 indicates it has the direct drive (or potted) motor. The 201 did come as a belt driven machine, but you don't see it very often.
I have seen other Singer machines listed as 221's on auction that weren't. Are you sure the serial number says it's a 221? Check
here for the number on ISMACS.