The bodies were built by Freighter Industries, JW Bolton, Hillquip and Howard Porter. There were some unusual O305s operating in Perth. Examples include 444, which featured a Mauri (Italy) body assembled locally by JW Bolton and 007, an experimental bus (model OG305) with an LPG-fuelled engine. In 1984, 008 Australia's first CNG-fuelled bus entered service. From the success of the trial gas buses, two O305s (270/1) were converted to LPG operation in the early 1980s, a CNG-fuelled O305G was ordered and entered service in 1987 as 009. In the early 1990s 26 O305s were converted to CNG.