OP has made his decision but the conversation continues which shows how interesting this topic is and how different the opinions can be. Basically the bottom line is the tire may have excessively oxidized OR the tire may actually be fine. Sure you could give it the ole thumbnail test but really the only way for us riders to know would be to mount it up and give it a go. No, you will not wreck on the first attempted corner. Well, at least not due to the tires age. If the tire has become to hard you will feel it and know based on how the tire performs and holds. Just the fact that you may mount up the tire and have to remove it after only a few miles will eliminate many riders. Some riders will immediately replace the tire. Hell, some complain about tires that are just 2 years old. Others will mount it up and go. Just like some riders use $12 a quart motorcycle oil with manufacturers filter and others use diesel truck oil with a Walmart filter in their bikes. Both work...it just depends on the rider. Whatever makes them comfortable and confident is the right answer. Just for future notice, if someone has a tire they are unsure of (age, flat or other) please do not simply dispose of tire as someone may want/need it. I have riders that want my take offs because they are worn on the edges but have plenty of tread in the middle. Go figure.