This early version of Kenner's Imperial Troop Transporter is notably different from the produced Kenner toy. The early prototype has flat edges and a significantly different sloped front end. It is a classic example of a "kit-bashed" prototype, meaning that parts were taken from other toys and model kits to assemble the components. Star Wars collectors will immediately recognize the Kenner X-Wing Fighter engine repurposed on top of the vehicle.
The Troop Transporter was one of Kenner's first toys for the Star Wars line that was actually not based on something seen in the movie. Since toys are frequently marketed to hit certain price points that consumers are willing to spend, toy companies frequently have to invent "off screen" toys to find a product that hits the range if there are no on-screen examples.
The original Imperial Troop Transporter came with a small comic book rationalizing the vehicle's significance in a Star Wars back story. This early prototype was also featured in photography available to retailers at the time and shares some of the main functions with the final toy design such as the 6 standing compartments, cockpit, and sound effects.
For more information on this prototype, check out the original Kenner spec sheet.
Make sure to check out Gus and Duncan's Comprehensive Guide to Star Wars Collectibles, available exclusively online.