EI from NCL
EI appears to treat NCL like JER - DUB is the only destination offered in the on-line timetable. Even EDI gets connections to JFK and IAD. However, given that most of the US flights leave DUB in the morning, EI would need the 0755 departure that's currently used by FR.
The exception appears to the the 14:10 NCL-DUB on Saturday, which, allowing for the odd wildcat strike by Aer Lingus ground staff, would give you sufficient time to catch the 17:00 DUB-JFK, and still have time for a beer or two in NY. However, I don't see a way of persuading the EI website to get you this on one ticket.
Can't have been more than 50 on today's EI305, and 40 last Monday.
So... it's either KLM via AMS or Air France via CDG and a few extra miles on my Flying Blue card. Anything to avoid LHR.