Pacific National is one of Australia's largest private rail freight businesses. Originally a joint venture between Patrick Corporation and Toll Holdings; it is now a wholly owned subsidiary of Asciano Limited following the restructure of Toll Holdings.

In February 2002, the mainly Australian Government-owned National Rail Corporation's freight operations and rollingstock were combined with the New South Wales Government-owned FreightCorp and sold to Toll Holdings and Patrick Corporation as Pacific National.
In 2004, Pacific National purchased Australian Transport Network, operator of TasRail. In the same year, Pacific National also acquired Freight Australia, operator of freight services in Victoria, giving Pacific National control of the Victorian non-urban rail track, excluding the interstate network which is controlled by the Australian Rail Track Corporation.

Source: Wikipedia

When the Puffing Billy Preservation Society was formed in 1955, the line was still under the control and ownership of the Victorian Railways (VR). The Society arranged for the VR to run the train on weekends and holidays, with the Society guaranteeing the VR against losses from insufficient ticket sales. Society volunteers took the role of conductors, checking tickets on the train, and fund-raising. This arrangement continued until the Upper Ferntree Gully to Belgrave section was closed in 1958.

When the line reopened in 1962 (between Belgrave and Menzies Creek), Society volunteers took a larger role, manning stations, selling and checking tickets, and doing non-safety-critical maintenance on the train, and track maintenance under the supervision of a VR ganger. Ticket revenue went into an account on which the VR drew to pay for their staff involved in running the line.

Source: Wikipedia