In response to a request from QW.
Behold a photo of a Transavia PL-12 Airtruck.
ZK-CWW was one of about 37 such beasts to feature on our register.
Pic taken at Dannevirke on 08-05-1971.
Have a look at the following link for much more on these beasts in NZ.
There is a complete example of one at the Ashburton Aviation Museum.