There's a reason that the expression "across the ditch" (or across the dutch if you are a Kiwi! sorry @KiwiNZ) was coined. Travel and migration between NZ and Oz in the late 1960s and 1970s was exploding and required little paperwork and provided many reciprocal arrangements (work, social security etc). I wouldn't be surprised if this butcher wasn't the only one travelling frequently at this time. Is this the suspected MJR? I thought he was discussed and ruled out? I remember, along with another WS member, commenting that anyone who writes Kiwi on a border control card has an antipodean sense of humour and disdain!
EDIT: Found it! Australia - Marion Barter, 51, missing after trip to UK, June 1997 #10
Thanks @gymtonic
I am coming from the angle that there is NO MJR married to IK. But WW using MRJ as an alias and just putting up what I find on NAA.
We had no idea just how many aliases RB used until recently so I don't dismiss anything he is capable of