I did a little research and found a very interesting (to me) report that explains the Border Patrol's $750,000 "Bronco Body off/Frame up Restoration Program (Restoration Program)", which operated in early 2001 and was responsible for rebuilding 129 Broncos out of a fleet of 1800 vehicles in San Diego.
According to this report, and my very poor reading skills, it seems that later, only 23 running (meaning not scrap) Broncos that had gone through the restoration program were sold to wholesalers, who resold them to the public. Each had an average of $10K spent on new mechanical components (labor was not included) and were driven an average of 19 months and about 14,000 miles beyond their restoration, before selling them in 2003.
This is all interesting to me because it means that my Bronco's indicated mileage doesn't necessarily reflect the wear & age of the major components. Good deal!