As of late I've been watching a Youtube creator, DiPDoT[0], building a relay computer.
DiPTDoT's project is still in-progress. His computer has an 8-bit data bus and a 16-bit address bus[1], like the Zusie. His registers are a little more generous than the Zusie.
I really enjoy the sound of DiPDoT's test rigs running his cards thru functional testing. The rhythm of a relaying computer running code with loops is probably pretty fun.