Claudi
The CAA told Phil that as it was a mil ac that he had 2 months to put it on a G plate or they would ground it ! The Irish boys strictly shouldn't be flying theirs in EASA land now. I am told that the FAA would not ben impressed that it is flying outside US airspace with no direct permission from IAA or EASA . Like all things you can do what you want til things go wrong.
Remember you cannot fly a permit to fly ac inside another countries airspace without direct permission from that state