The Dove at Morabbin is VH-ABM, formerly operated by Maloney Aviation of Essendon - hence the Penguin Express logo. It is a Riley Dove, which means, among other mods, it was fitted with Lycoming IO-720's in place of the original Gypsy Queens.
The other Maloney Aviation Dove was VH-NBM, another Riley Dove. NBM is currently at Wallan ALA and, like ABM, appears to be derelict.