I've conducted quite a few of these either as combined IR/IPC or IR(R)/IPC - it's within both sets of regulations since in both the EASA IR/IR(R) revalidation/renewal and the FAA IPC you are being asked to demonstrate proficiency in those tasks.
You will need someone with a UK-issued EASA Flight Examiner with IR(R) examining privileges who is also a current FAA CFI-I: there aren't many of us about.
ifitaint...