The site below says it was made in 1948. Hope they help! Post and let me know, please.
http://www.singerco.com/support/machine-serial-numbers/double-letter
http://www.tandtrepair.com/Singer221/221LGR.pdf---says it is a FW:
St Johns, Canada machines JB 1945 to1948
JC 1948 to 1959JD 1959 to 1963