If you're interest is for show purposes, fine. Do the shoe polish thing.
However, if you mean "restore for actual use", then you should consider rethinking it. The rubber/nylon carcass of the tire deteriorates with age. Not only does it become structurally compromised (cracked), but the rubber also hardens and becomes less compliant - and has less grip. Hard tires also don't grip wet roads well either.
Now, I'll point out that when this question comes up with old cars (like ones that used Michelin TRX tires - which are analogous to Schwinn sizes), I'm usually very adamant about not risking the car (or the occupants) with ancient rubber. On a bike, obviously, the speeds are much slower and the results of a tire failure are a lot less catastrophic. You could get away with it just cruising around, doing parades, etc., although if you have chunks of side wall pealing off, then just replace the tires.