Paul,
You are probably quite right about NZ importing those ads, as they sound quite familiar.
A lot of that sort of thing was brought from the UK, back then.
I'll never forget that Caravan Safety ad though, this is where Dad hooks up the family caravan to a socket-outlet in the house, but the flex he's got is too short, so he makes up another one and plugs it in.
(This was made in NZ, as it featured an old PDL 30 Series Outlet with no switch).
And then one of the kiddies goes to open the door on the caravan, and I don't think I have to explain what happens next, but it stuck in my mind for years afterwards!. [Linked Image]