I can't reliably offer one of mine as I know I'll get delayed and leave you waiting, but let me make clear that if anyone wants to make and sell my design of an AR488 PCB (
https://oshpark.com/shared_projects/yfUOmUzA) then it's fine with me. It's an open design and you can do what you like as long as it doesn't restrict anyone else's use.
I assume the same is true of WaveyDipole's code but i'd recommend you check with him.
@The Soulman It's really pretty easy to build that - you just solder a 32u4 arduino and a socket on a pcb, and program using the arduino suite which is also painless to learn. But I take your point about wanting a known-working interface when you're trying to set up another part of the system.