I recently picked up a fuchs spare clad with a (zero mile) Dunlop SP 57 185 70 15 tire...still has 100% tread and all the little "nubs". It was actually mounted with an inner tube! The wheel was never mounted and dated 3/72. As the wheel was never mounted, I am going to assume that the tire is as old as the fuch. To be clear, I am keeping the fuch, but have no need for the tire.
I am not a tire expert, and I don't know what to look for on the tire that would represent a code to determine it's actual age. Tire looks great as it never saw asphalt or the sun
If you can use this let me know, and we'll figure out something silly to trade.