I agree with you on the Nikkor f/2; it's the best 50 I've ever used, or at least I remember it that way. I've never used it on a FF Canon but your posts have inspired me to get a F to EF adaptor and get my old Nikkor 50 f/2 into digital action. Unfortunately the focus ring on mine is now quite loose but maybe I could have it serviced and re greased.
Funnily enough this lens is almost a pancake design, set into a conventional 50mm f1.4 barrel.
Given that you have an adapter I'm surprised that you haven't got hold of a Nikkor 105 f2.5. This was / is a superb portrait lens, and had a stellar reputation in its day.