Serial number dates the machine to March 1940. Singer did cricle finish in those days, and from other machines Ive seen Singer kept the part that covers the motor belt in a shiny finish (the black part over the hand wheel). Yours looks original; you can look for traces of a possible previous finish under the base where the paint overlap the bare cast iron.
Needlee and presser bar will polish up like new the right stuff. Does it turn smoothly?
The intersting part with yours, is the top tensioner doesn't have a dial, and this late I thought most machines did. Your have the earlier pattern on the chromed plate, I like it a lot. The later straight stitchers were given a hinged presser foot, yours have the earlier one piece metal version. I have it on my 99, it work fine, the same tensioner too. I haven't seen that type of motor before, 66 usually have the horizontal type lamp, yours have the round spot light version. If it still has the glass lens, go for a LED replacement, it's less hot. More than 15W old type incadecent bulb will ruin the lamp.
Last edited by Mickey2; 03-21-2018 at 02:21 PM.