I'm glad you asked these questions, because I had similar thoughts - when it says "front of the plug" is that the plug itself, meaning the pins, or the front of the socket? Glad you anwered that one or I could have had some serious voltage problems :P As for the design of the PSU itself, I was a little confused too - my own C64C (late model that I'm too attached to to take apart) had a square power supply with fins across it and an embossed C= logo, in the same grey/beige colour as the computer. I bought a Mk1 C64 (light brown, dark brown keys) expecting to have a wedge-shaped PSU and instead got one the same design as a later one, but in black. It outputs the right voltages to power up the C64 though, so guess that's what matters. My question, is the optimised PSU schematic usable for 6581's, 8580's, or both? Thanks, Dan