it was one of those oh crud moments (Tire recall see p.5)

Wow, great follow up.

Back in the 70's Firestone bias ply's had problems of sidewall de-lamination .. .... I had them on our camper van. We were on vacation, stopped at a gas station, saw about a 2in dia. bubble on the side wall of one of the tires.
Short of it, Firestone denied any wrong doing, I replaced the tires with Goodyear... About 3 years later Firestone owned up... We had sold the van, and the paper work was gone....

Jim