Beagle,
The HRS/MRGs were the same as on the Blue Steel missile with the advantage that we did not plan to sling them away half way through the sortie.
I thought that they were liberated from the TSR2 programme as indeed was the Decca Doppler 72M.
The guy responsible for the HRS in the Vulcan was a Sqn Ldr Harris at 1 Gp who made the case and won the battle.
The Ligntning may indeed have had them too but for a different purpose. In the Vulcan it was used for heading whereas the Ligntning used it for attitude.
I may well be wrong on this but your input excited a few unused brain cells.