Skytruck,
Unless things have changed recently or there is a special waiver, such that allows Icelandic companies into the UK market, then Ryanair would have to get around the EU Right Of Abode regulations for any non-EU pilots, the same way Companies have to for Americans. No major axe to grind here, just facts. I believe the IAA are fairly helpful doing this. My Company has some young Dutch First Officers, an EU country after all, and first rate they are too.