You are very lucky and blessed to come out the other side of this without damage to your m/h, yourselves or others. You seriously need to think about that.
This blow-out could have ended with a horrific crash that could have taken out an entire family leaving a tragic mess behind for others to clean up and live with. Driving with 8 YEAR OLD TIRES just because they look good is irresponsible at best. Especially in a motorhome that outweighs most vehicles on the highway by TONS.
Instead of thinking about "Gettin another year outa these old tires" think about the people you are endangering on the highway and the children you just might kill in a wreck you cause by having dangerous old tires.
I'm sorry to be harsh here. This is a perfect example of people that put their wallet ahead of common sense and safety on the highways.