Considering all the hassle and paperwork generated by European pilots trying to use FAA IRs as a shortcut to JAA IRs. Not to mention European pilots operating 'N' registrations in Europe, the JAA authorities trying to dream up schemes to stop them and the FAA fretting about the extra workload.
Might we persuade the JAA to pass a rule saying:
"A JAA pilot can use the privileges of a FAA IR on a JAA registered aircraft on a non commercial flight."
The FAA IR holders will be doing what they do anyway but no longer under 'N' reg, so less hassle for all concerned.