Information: The company was apparently boat builders who turned out the occaisional van or two in the years after WW2. They were in Melbourne The lights are brass rings around frosted glass domes (3"/75mm Dia) The gadget buffs will like the "pop-up" vent. This is operated by twisting a handle over the bench..attached to a dowel that runs through the roof! A very early "Robin Hood" range hood! The picture also shows how 1/2 round timber edging was used!..this is one of the "little" things that grabbed me...
There are also one or two other references to Botterill & Fraser on the web relating to boating. This provides some confirmation of Jazhow2's comment that Botterill & Fraser were (primarily?) involved in boat building as well as building caravans.
For more information and photos of Jazhow2's Botterill & Fraser caravan click here
For photos of another Botterill and Fraser caravan owned by Impalaclick here