Can we find who owned the property in 1973? As landlord, they should be able to give info on who the tennants were.
AnnasMom, I know hearing this now is probably upsetting. But I am guessing that with the chaos that probably occurred after she disappeared, and the grief that all were going through....most likely this was probably mentioned to LE and when they dismissed it, it was probably forgotten. After all, why upset you more with what was thought to be useless information? After all they had not found anything concrete. Looking back now, with her disappearance still unsolved it stands out more than it would have then.