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 and I was also helped enormously by some other modelers who provided their private photos. Those photos helped a great deal in detailing components.
A visit to the Brooklands Museum would help, but COVID has made 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.
Courtesy of http://graememorpeth.com/
Below are the most relevant, and also very helpful, engine drawings. But note they are somewhat different than the XIA configuration used on the Napier-Railton. Click on them for full screen popups: