Cool, it looks like you've made a kind of power distribution backplane where you have individual modules produces the other voltages? At least that would easier to troubleshoot in the future. So you're basic plan was the get a main 12V AC-DC PSU module, then design a board that passed that 12V through and took needed 12v power to produce the other voltages. Did you have a plan to modularize the "system specific logic" of this PSU in one of those neat edge connectors? Like a plan to create a basic platform you could refactor in size and shape (for other SGIs, like the O2), and use a module to emulate the non-standard signalling lines?