Complex sentence: At Clonbinane, mail had to lodged by 0900 hours to reach Melbourne's GPO by 1525 Hrs. The time-frames would suggest mail was routinely carried by train during the period, probably between Melbourne and Wandong.
Split into simpler sentences: At Clonbinane, mail had to lodged by 0900 hours to reach Melbourne's GPO by 1525 hours. Those time-frames suggest that mail was routinely carried by train during the period, probably between Melbourne and Wandong.