To take this one further:
Assume you hold a FAA CPL/FI and a CAA/JAA PPL. All flights in the scenario below take place in JAA airspace. Can you:
a) instruct and do BFRs (FAA) in a N-Reg a/c ?
b) instruct and do BFRs (FAA) in a G (or other JAA) reg a/c ?
The FAA part is clear, as you hold the requsite license(s). But can you do it in JARland ?
Discuss.