Yep!!! Lucky you....that IS a Featherweight! :thumbup:
You can check out the year of manufacture using this site:
http://www.singerco.com/support/serial_numbers.html
You can also check out Dave McCullam's site Featherweight Rx:
http://www.featherweight221.com/fwrx/index.html
His book is priceless to have if you own a FW. It's written so that the average Joe can maintain their FW and save themselves some money at the repair shop: