Rich Camarda has create a reproduction of the Cromemco VPU described at http://s100computers.com/Hardware%20Folder/Cromemco/Z80/ZPU.htm

The manual from s100computers.com is here: zpu_manual.pdf

Bob Darlington has created the following BOM: https://docs.google.com/spreadsheets/d/1RPuvHZZdrBqugLGMoNXTaFcthmXeuTu5lbAt11k2UqM/edit?gid=0#gid=0