Hi
I am sure I have seen a picture of the fire truck, perhaps on one of the Story DVD's
Accordind to
www.microcarmuseum.com"1957 Isettacarro
Renzo Rivolta's little Iso Isetta, immediately attracted attention, and licenses were granted to build them in several countries. Two models were offered - the little egg-shaped Turismo with narrow 50cm rear track, and the Type Autocarro, a commercial version with full-width rear axle.
The Autocarro was offered in several body styles, a flatbed pickup, enclosed truck (Furgone Commerciale), a tilt-bed, or even a fire engine!"
Could this have been the base?
John