Old sewups are always a crap shoot. As but one example, I bought three tires one time of about the same age as those you're contemplating. All three held air just fine for me up to my desired pressure of about 120 psi, so I figured they'd all be fine to ride. And off I went on my 1981 Raleigh, one of these on the front, another on the back, carrying a single spare sewup as I always do.
The first one lasted about 5 miles. The second one lasted most of the rest of the ride (another 30 miles or so) but flatted a couple of miles from home and I had no spare, so I walked a bit, called my wife, and she was nice enough to collect me. That's the only time I've ever had two flats on the same ride.
I've had others that have held up just fine and I don't find any way of predicting based on appearance of how well they hold pressure in the shop.
As they say in Italy, buona fortuna - good luck.
> Hi there,
> I have an opportunity to buy 15 to 17 years old sewup tires, namely Clement
> Criterium, Continental, and Barum tires. They are new and never ridden, and
> for those years in southern California (Orange cuonty). Owner says they are
> still flexible and seems hold air (but not tested for full pressure).
> Are they good enough for display only, or good enough to ride on?
> I appreciate any input on this matter from fellow mewmber who knows about
> those sewup tires.
> KEN TODA, High Point, NC