Great to meet you here. For general discussion on historical Unix I can recommend The Unix Heritage Society's mailing list (maybe you are already a subscriber).
My personal favourite retro machine is the TI990 mini and derivatives. I have done a Unix port for that - maybe you will be amused to hear that I hacked your 1970's Interdata assembler into a TI990 assembler a decade ago, and I'm still using that.
More to the point, I've been intrigued with the idea of doing a Blit on an FPGA board, the BlackIce MX or the Ulx3s, or maybe both. Through the efforts of @lawrie it has been possible to do a M68000 model that works with Yosys and building on that there now is a model for a small M68000 system with 16KB of rom, SDRAM for ram and a 6850 uart. That is already close to a Blit without video circuit.
The video circuit is quite straightforward. Rather than 800x1000x1 I'm thinking about 1024x768x1 digital video, or maybe 640x480x1 to start with and keep it super simple.
All that said, I unfortunately do not have the hobby time right now - late Summer should be better.