Although the two Setright ticket systems (Insert and Speed) dominated Central SMT throughout its history, the company did use other systems.
In the late 1960s, rather heavyweight Almex machines were tried. They did not last long on the buses themselves, but were soon withdrawn and relegated to agencies, where they continued to be used for many years for issuing weekly tickets, etc. (At least, that's my memory of the situation - the two single tickets shown suggest otherwise!) The Almex machine produced the characteristic square imprint and tickets had to be designed accordingly. The weekly ticket shown has one imprint area that is suitable for Setright only and another that is suitable for either Almex or Setright use.
Although Setright ticketing quickly became the standard for one-man- as well as crew-operated routes, initial conversions of town routes involved the issue of pre-printed tickets from Bell Punch Solomatic machines.
In the 1980s, Central made a phased transition to Timtronic electronic machines, which calculated the fare based on the current fare stage and the destination. This took a bit of getting used to, as most passengers were in the habit of asking for "thirty-seven, please", or whatever. Buses carried notices requesting passengers to "Please State Destination".