Originally Posted by clubman

Yes it's a Humber chainring, those are usually referred to dancing people. Regarding price, it depends on your market. An incomplete bike certainly won't get $300 anywhere. The lack of original chainring doesn't help either. As gster suggests, those are tough tires to find. The 26 x 1 3/8 - EA1 -S6 is a US sizing and you'll have to find the Schwinn specific tires I think. There were a few Dunlops that had the same markings that you refer to but they're not common. You want a 597 mm bead, NOT a 590.