As mentioned, I had two incomplete keyboards. Each was mostly complete with a couple keys/switches broken. Intentionally I had bought two with complimentary keys missing. So, I selected the PCB with the cleanest switches to be the base for the build. I only had to swap three switched. The big through hole parts and my Hakko FR-301 desoldering tool made the work simple.

After that, I simply covered the back of the PCB with some electrical tape to minimize the chance of shorting something out since the PI was going to be located below the PCB.