Congratulations on getting one of these jewels. I love my FW for piecing. I take it to workshops and classes.
Dave McCallum at
http://www.featherweight221.com/ has a great book and DVD on the care and maintenance of FWs. He also sells parts.
Another site for parts is
http://www.221parts.com/.
Schmetz needles will work fine in your FW. You can also quilt with your FW, but the small throat area makes it hard to do anything much larger than a crib quilt. You can buy a walking foot at 221 parts if you want to do SID.
According to
http://www.singerco.com/support/serial_numbers.html, your FW's serial number was released for production September 16, 1946. Also, it was manufactured in the Elizabethport, NJ factory, so I'm not sure where the conversion comes in, unless someone took it to England and had it converted to 220, then returned to the US and had it converted back to 110.
There is a FW group in Yahoo! Groups.