Thanks to a dedicated group of enthusiasts over on the Acorn Stardot forums, an original Domesday development machine has been imaged and the hard drive contents are now available on this website. The original machine was an Acorn A500 (a prototype type of the Acorn Archimedes) which was used by Logica (the company that originally developed the Domesday project for the BBC).
The images contain a lot of source code for Domesday including build environments and tools. There hasn’t been time yet to go through all of the content in detail, but expect more information as it becomes available.
You can read about the find and download the hard drive images from the following link.