From reading the op, surely Mr Arik is looking for an instructor, and is asking what qualifications he should expect such a person to have?
Arik - As Chevron implies, it's fairly complicated and (UK-wise) sounds like it would involve an Assessment of Prior Competence (API) and aspects of an APP/APS course, all of which would need to be "approved" by the CAA.
First ports of call would be CAA (obviously!), NATS College of ATC and the college at Cwmbran (not sure if it's ASTAC or Bae)
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