I found this nice Matchbox King Size, along with another larger (than 1:64) scale model, at an estate sale back in July. They were marked $4 each, but it was half-price day, so I got both for $4.
Matchbox King Size models (in the 1:43 scale range) were introduced in 1960 and most featured moving parts or opening doors. In 1971, the King Size range was separated into Super Kings and Speed Kings. This Speed Kings Fire Control Range Rover is from 1978 and features lots of nice details, off-road wheels and an opening tailgate. It was originally sold in a box that would have included two firefighters, a ladder and a section of hose that could be attached to the vehicle at the front or the back.