Note the wings & tails have been removed from the fuselages.
That's because the USMC's AV-8B+ have a different fuselage from the GR.7/9s, but the wings & tails (and engines) are the virtually same, and can/will be used (with refurbishment) to keep the USMC's Harrier IIs operating until the currently-planned 2030 OSD.
I know I've posted this before, but it never hurts.
The 1990 radar "upgrade" to the AV-8B:
