... a pair of Nike Air shoes in the unpressurized hold of a lear 31A did not survive FL430. One of them had burst the shock absorbing air chamber, whilst the other survived. But what good is one shoe?
Regarding footballs in the cabin, leather vs. rubber footbals, one should consider that the rubber footbal being more expandable, it should have pressure differential increase less that the leather version.
On a more important note than 7 or 8 thousand feet, how about a cabin depressurisation at FL410?