Udo Möller's website seems to be the place to go for NS32000 series computer information.
In it, there is a page about an NS32008 project by a chap in the USA called Vince.
He has made a 4-layer board which works and has gone live in this video. The signals are toggling but it does not show any code running. Not a concern this early.
Vince has more boards than CPUs, and has kindly offered me one. I shall take up the offer, and that will save me the chore of wiring my own prototype.
For firmware, I shall be looking at the Acorn BBC Micro 32016 second processor firmware and Udo's Windows-based cross-assembler. Maybe I can disassemble the former to create source code I can hack to drive other devices.
I have just downloaded Udo's cross-assembler onto my Windows laptop.
Jonathan Harston has a 32000 disassembler but it is written in BBC BASIC. Nice if using the beeb for development but my Linux PC is more convenient. Maybe it can be re-written in C or C++? The instruction set is said to be orthogonal so there would be fewer special cases to deal with.