Yours looks like an aftermarket wheel. As far as I know Singer used cast iron for their wheels. Yours looks like aluminum or pot metal. I would also expect the finish to be about the same as the rest of the machine. Paint is flaking of the wheel pretty heavily. Your machine was probably electrified in the 1940s. A lot were then.
That's the first flat bobbin winder tire I've seen. I wonder if the diameter of the hand wheel is a little different than the stock wheel where the tire rides? That might explain the tire.
Nice gift! The bed decals look like they're worn off but the rest look pretty good.
Rodney