The Calc 3 (the bombing part of the NBC for those unfamiliar) was removed from the K1s around 1973, and also from the B2s on conversion to K2s a year or two later. At the same time the R88 camera was removed much to my regret, as the foam head rest was ideal for the nav radar to lean on when having a snooze in quiet periods
A-A Tacan did have bearing as well as range. We used it regularly when RVs were not being assisted by ground radar.
Thanks for the info on single nav
OSA. My old plotter and I were wondering about that when chatting on the phone the other day. I remember seeing a photo in the RAF News of a nav taking the very last Gee fix before the system was shut down. I wonder who took the last fix off the H2S.