Thank you very much, PIGDOG. It's good to know that I can eliminate the SELCAL identifier, at least with Shanwick and Gander.
I must say I do enjoy the level of service provided in the north atlantic compared to, say, NOPAC (no offense to any Oakland/SFO ATC reading this). I cross the Pacific much more regularly than the Atlantic and probably would not omit the selcal over the Pacific; they still ask for things like aircraft registration, departure and destination, etc on initial call-up! It's also difficult to get reliable handoffs to HF in the NOPAC, at least in my experience.
Anyway, thanks again, you've been a big help; maybe next time I will actually sound like I know what I'm doing when I call up on the HF.