Newt,
And I'm sure they were fully airworthy when they landed at Cranwell!
They've been at Cranwell for eons and long before Jag went out of service!
Now if you're really worried about Jags being flown in for ground training, the 2 at Syerston (just visible from the A46) were flown in and decommissioned to allow IOT cadets to 'task' and 'guard' them during the final exercise on the new (in 2007) IOTC!
So, they are being put to excellent use at no cost and are, technically I suppose, still 'in service'!
Foldie