I may be wrong, but I heard somewhere that they are all owned or contractually obligated to Boeing in exchange for a good price on the B-757PF 's that UPS bought. Therefore the will not be operated by anyone else, rather they will be scrapped when UPS is done with them. Hope it's not true. One of my glider instructors was in International Sales at Douglas Aircraft Division of McD, and said that UPS once approached Douglas for a price for 60 new-build 70-series DC-8 Freighters. A price and schedule proposal was to be worked-up but it was discovered that the facilities manager in Long Beach had sold the DC-8 production tooling for scrap, ending the possibility of more 8's. He was supposedly fired on the spot. UPS then approached Boeing for B-757 freighters, and got a deal, with "terms".