Two J4 airframes (G-AIPH & G-AIJT) were modified with Continental O-200 engines in the late 1960s by the Rolls-Royce employees “Merlin Flying Club”.
In the late 1960s, two J4 airframes (G-AIPH & G-AIJT) underwent modifications to be equipped with Continental O-200 engines by Rolls-Royce personnel referred to as “Merlin Flying Club”.