1933 Napier-Railton Drawings
My goal was to build a chassis model. But, as is common with pre-WWII vehicles, original drawings were very hard to find. Sadly, it also appears that there weren't any drawings from the full restoration of the vehicle that took place in the 1970s. Fortunately, there are better drawings available of the engine, although you have to be careful because there were several different variations.
Below is the one contemporary profile sketch of the car. Apart from that, the CAD drawings have been constructed using the few known vehicle dimensions, the engine dimensions, and as many photographs as I could find. Fortunately there are a lot of exterior photographs available on the Internet. They helped enormously with some of the components.
A visit to the Brooklands Museum would help, but COVID makes that difficult. Meanwhile their staff are trying to help.
A rare high fidelity photograph of the open chassis:
These three poor quality photos are from the 1970s restoration.