She looks lovely! Very similar to my FW which was my dear late mother's and the one I learned to sew on as a child of 8 or 9.
My manual say 221-1 and I have a receipt dated August 1947...bought for $49.00 in the NYC area.
Those letters/numbers look like: 2253 - - - ??? I believe, if I recall, there is also a tag/plate somewhere that says whether it was "made in England" ...
Take the bottom off... you'll have to do that anyway to oil and lube it. FOLLOW the DIRECTIONS IN THE MANUAL. I have one but you're lucky to even have the cover!!!
Good luck.