Ten for NAI (EI-reg), one for NUK (G-reg). However the NUK aircraft operates using the D8 code and 'Nortrans' callsign, but with a separate crew set from the NAI operation (but on the same terms/conditions as NAI). All very complicated.
I believe the single G-reg 737 operation was simply an AOC 'sitter'. Now that the entire LGW based long haul operation is moving to NUK, I'd imagine G-NRWY could return to the Irish register. But with Brexit around the corner, who knows.