Avenger is correct - and while I haven't looked at this stuff in a while I'm surprised to learn it's now even more restrictive at 3 years and not the old JAA 5 years from expiry before being required to do the full type rating again.
Personally I'd email both NAS and RYR to ask what they'd need for you to be in a position to apply. Even if you got the 737 back on your licence off your own back, RYR would probably treat you as a cadet in terms of training once you join. The OCC courses are for current type rated people. Course you'd get a command within a couple years most likely as your previous experience doesnt expire, but I'd email them beforehand. If you're going to pay for a full type rating, you might as well do it only once (as RYR would make you do the full course as you're not current) and pay Ryanair as a cadet.
You should just apply for RYR right now the more I think of it.