There's a 7 in both. I once accidentally redelivered some mail which had ended up in our box to Railway Parade instead of Station St.
Hall St and Rushall St are only three blocks apart in Fairfield, so it's perhaps not altogether surprising that I occasionally get mail for the former.
Presumably Australia Post uses automatic scanners/sorters which I would have thought would look for the post code first??
Meatloaf a diplomat, ha ha.