$40 is okay for it. Quite a bit more if it has a working 2-speed kickback hub. (probably not if the wheels have been changed)
Attempting to do a show room resto on it isn't financially sound so do what you want with it.
the original seat would have the big S and should be painted white on half, matching color to the frame on the other half. All black and it's a replacement.
original rims would be chrome or painted, depending on year and if it's a regular Typhoon or a Deluxe Typhoon.
The main issue for Schwinn middle weights is tires. 26 x 1 3/4 (fractional) is not the same size as 26x1.75 (decimal). Fractional tires can be a challenge. Old and crusty, 14yo repops for $100-150 each, or ill fitting modern cheapies for $40 each. But if the rims/wheels have been changed out, they might be decimal rims now so there are endless tires available.
I rebuilt an 1950 Schwinn Ace with aluminum rims with 2" slicks and it rides far better. Cutting the rotating weight really helps.
you can look the serial number up to get the year & month of production. Then find the matching Schwinn catalog page on the www to see what was stock when new. Schwinn changed the sprocket design from the clover leave pattern to a mag design around 1970.
rick
my middleweights
Ace, American, Hollywood, Typhoon, Typhoon
sold:
Starlet III, Flying Star