Yeah that is interesting...my one mfd era metric/whitworth board has a panel number and then a serial number... I would guess they started this in the mfd era, just like the op's board. None of my proto la boards (4 of them) show a serial number on them , either on the front or back of them.Very cool! I love the half width boards. I’m curious about when they started serial numbers. All of my boards are LA era and none of them have one
How is this coming along ? Have you started filling this up with impacts?