I just watched this for the first time since I was a kid and it was hilarious! When Preston is talking to Curie in the train and he says, "What was I saying?" and she says, "Small?" while wiggling her finger.. Pure gold. I loved how there are jokes which you just don't get as a kid - something there for the adults as well. Also there are some great appearances by Aussie actors who later became big names (Sandman, Georgie Parker, Mikey Robbins, among others). They just don't make films like this anymore ;-)
Not seen this for yonks. Just got thinking about old films that I loved as a child and this cropped up in my head. Love the scene where he blows up the shed and the bathtub violin playing!