Pardon this mere civvy joining in.
Putting those three airframes on a US military register may well be a solution to this particular issue. However, what remains to be solved is a deep systemic problem in the MOD/RAF. It is probably the case that those three aircraft are airworthy and suitable for the intended purpose, but they are haunted by a series of disgraceful and deliberate lapses in proper airworthiness maintenance.
I wonder if the powers that be in Whitehall would be willing to admit our shortcomings, accept that we have lost a degree of expertise and accept help to restore a meaningful airworthiness certification capability.
In the meantime, whilst admiring the truly gallant efforts of all military personnel at the sharp end, they deserve better. I have lost all faith in the top table.