Jon,
I thought that I was doing good because I had 2 different size air bags in my coach inventory. When the tech removed the bag that burst we discovered that NEITHER of my bags were the right size. Newell is overnighting 2 bags that will fit the drive axle front (one for a spare). You are right on with the 10 year life of air bags; I am changing the other 7 as soon as possible. The tech and I looked at the other bags and they look o.k., but I am still going to change them.
I can't emphasize enough the need to carry spare parts.