Forgive my ramblings, but MB's name change being the major difference to all the other cases we know about..
Did MB know RB as FNR, even if she was aware this was an alias, his passport was in the name RLW at this time?
Was it her idea to change from MB to FNMR (knowing that Luxembourg wives do not automatically take the husband's surname and she wanted that married name status)? Did she tell RB before either of them left Australia?
Or did he find out when they were together in UK, that's presuming they did meet up at some point?
Did RB want her to change to FNMR (eg to fit in with an MI5 story?) to enable access to MB's funds, foiled as MB did not name change her bank accounts? The name change would prevent MB's family being able to trace her easily, but officials at that time would have had access to her paper trail after her disappearance (if of course, it had been taken seriously) eg the dentist signing the name change passport application?
Lastly, did MB leave Australia again (after withdrawing the money) with a fake passport acquired for her by RB?
No answers obvs, but my feeling is MB inititated the name change, she then had to 'disappear' because, at the time, her name change could be traced back to the FNR driving license (unusual name) and therefore back to RB, not part of the plan. Having said that, there were no consequences for RB after ladies that were conned went to the authorities with their complaints...so I am doubting my argument!