I agree with the other posts, they're way past their use by date. I recently picked up a 1958 Citroen 2CV in Paris. It had last been used in the early 80's. All the tyres held airand looke OK, I winched it up onto my car transporter and strapped it down. I use ratchet straps with a secondary strap so I strap on the tyre itself. I got about 10 miles and there was an almighty bang as one of the tyres spontaneously blew.

This was a car just standing on a flatbed transporter, the only additional strain was from the strap! Don't risk it.