WTB: Schwinn S-6 Tires (26")

Looking to buy or find a place that sells Schwinn S-6 tires and tubes for our Schwinn Twin Tandem. I think we can use regular 26 x 1 3/8 tubes, but the tires are getting a bit worn and rather than buying online, was wondering if anyone had anything like this for sale locally or know of any local bike shops that might carry these. The tires do not have to be NOS, it's just that our tandem is "original" including the close to 40 year old tires.  I know it's a long shot and we will probably need to go online, but wanted to give the forum a go since you never know what people are collecting. 

I have found replacement tires and tubes on Amazon.com already- just seeing if anyone deals with this old stuff locally. 

Thanks-

Melanie & Robert