Invalid Car 4mm Scale Model - Part 1

In 1964 Broad Clyst station in Devon on the Waterloo-Exeter mainline was a loading/dispatch point for invalid cars. They were carried on open Lowfit wagons and would have been a common site on the main line. I have a photo of a mixed freight train (1962) with one lonely invalid car, probably on its way back to the factory for repair as the train is travelling towards Broad Clyst on the down line in Somerset . This train I can re-create in 00 gauge but I need an invalid car. 

There were many manufacturers and styles of invalid car over the years. I tried tracing the car manufacturer from the Broad Clyst area with a view to identifying the actual 1960s car model, but to no avail. After close examination of railway photographs, showing the car in the distance, I have chosen the AC model from 1965 as this car had a distinctive curved underbody at the front, which is visible in railway photographs of the period. 

Trawling across the Internet revealed a number of good images. Here are two: invalid carriage register and flickr. The bodywork of my model will be carved from balsa wood.

Part 2