Every time I see someone spending four hours desoldering crusty CapXon capacitors from some generic 200W push-button AT power supply, I lose a little more faith in our collective sanity. You are risking your expensive retro compnents on a design that had terrible ripple suppression when it was brand new, let alone now. Yes, keeping the original power switch click is great, but you can easily wire that mains switch to trigger a modern SFX unit instead. Emptying the old PSU chasis and mounting a high-quality modern SFX supply inside it takes half the time of a full recap. Plus, you get actual working over-current protection that won't dump 12v into your precious Socket 7 board when a silicon diode decides to short out. Stop hoarding these ticking time bombs just because they have a pass-through AC outlet on the back. It is not worth the risk, and those old group-regulated designs handle modern 12v-heavy loads horribly anyway if you are doing a sleeper build.