FAA 'piggyback' licence to allow me to fly N registered aeroplane
Correct.
JAA licence to allow me to fly anywhere in EU
Not correct for an N-reg. FAR 61.3 allows an N-reg to be flown in any non-US airspace provided the pilot has a license
issued by that country. JAA licenses are still
issued by one country; they are
validated by the other JAA member states. So to fly an N-reg in say Germany you would need a German issued PPL. This is a grey area (and the FAA have expressed both views on different occassions) but this is the literal interpretation.
That my JAA currency maintains my 'piggyback' licence currency without need for the FAA biennial, notwithstanding the fact I am in a US aircraft?
Correct, I think.
Make sense to anyone? Thanks for any advice!