Re: F-35B--the "B" stands for boondoggle!!
' U.S. Marine Corps sells Britain back the now thoroughly worn-out Harriers'
Don't worry, the USMC haven't put a single flying hour on them*. They have stripped them for spares though so they're not exactly in a fly away condition anymore.
*I believe there were sufficient differences between the AV-8B and the GR-9 that integrating them into the USMC fleet would have been a massive headache. i.e. you'd need a bespoke supply chain for the GR-9, which even if you only had certain squadrons fly them would be a PITA. So it was simpler to use them to increase their holding of spare to extend the service life of the active fleet.