I've been building PCBs for this series in my spare time for the past couple months, this last weekend I finished the design for the ALU: https://github.com/lelandbatey/custom_cpu--ALU

I've then been having them manufactured in China for, which you can have done for ~$15 for 5, shipped. It's very satisfying to have finished fancy PCBs to solder together, and I've learned so much about electronics, PCB design, and small scale board manufacturing since starting this project!