Early Pins DP-2
Early DP-2s had pins to connect two circuit boards together. It was a neat idea, but not very reliable. Therefore Nikon replaced the pins with wires, and wrote a white paper to retro fit the pins version. Here's before I retro fitted a pins DP-2 with a parts wired one of similar vintage, to make it 100% 'original' for a customer.
Wired and pins DP-2 versions