Yes it was Vulcan's and I was stuck in Singapore. ASAIK they were based at Darwin and flew some cracking exercises there. I think they went down to Perth that time.
In UK the bombers used to fly 'fighter rules' ie simulating the enemy bombers. Not too high, not too low, and nice and level.
In Oz, totatally unrealistically for the OZ jets, we were able to fly bomber rules. Not too low, about 55K plus was comfortable, not too high, less than 300 feet was perhaps not unheard of. Plenty of open air space to no jammer restrictions.
Flying above the contrail level and jamming the height finders was great. The fighter controllers could 'see' all the bombers but they were 'invisible' to the fighter jocks as they were simply looking in the wrong place.
When you are capping at 30-35k it is a long way up to 55k.