Here is an extract I found on the ICAO website:
International recognition of flight crew licences
The Convention on International Civil Aviation, often called the Chicago Convention, provides for worldwide recognition of flight crew licences issued by any member State of the International Civil Aviation Organization (ICAO) provided that:
1. the licence meets or exceeds the ICAO licensing Standards of Annex 1 – Personnel Licensing to the Convention on International Civil Aviation; and
2. the licence is used on an aircraft which is registered in the State which has issued or validated the licence.
If the licence is to be used on an aircraft which is not registered in the issuing State, the licence holder must obtain a validation of the licence from the State of Registry or alternatively obtain a new licence issued by the State of Registry.
The international Standards on Personnel Licensing are contained in Annex 1 – Personnel Licensing to the Convention on International Civil Aviation. Annex 1 can be purchased on-line and at certain locations. Annex 1 can be accessed on-line by subscription.
ICAO website
Anybody got an ICAO subscription?
In fact guys, the more I read and think on this, the more I suspect this CAA is breaking ICAO rules. According to the above convention (to which they are signatories) they are obliged to accept another member state licence (if valid) and THEN apply whatever tests/exams they wish to grant a validation/conversion.
It would appear this CAA is saying - 'We see your licence is valid, and issued by another ICAO Member State - but we don't accept their State Approved Inspectors signature on the document alone. We want further evidence before we'll accept it. We want the Check Pilots scribbled notes. If you don't provide them - we don't recognise your licence.'
Is that not illegal under ICAO?
I certainly think its sailing close to the wind.
Of course, ICAO/IFALPA would have to take it up and challenge it!