Try to relocate that fan to nearest the most sensitive components - the ones you have to replace because the originals are junk - the two large capacitors. It cannot be done, so a secondary relay fan is necessary. The heatsink is a weightsink, a sinker. A proper exruded heatsink would cut ONE POUND off the weight and cool better WAY better. Heat sinking is about area radiation not bulk weight.
I do not know what other power supplies use for capacitor grades but I'll say this. By going to ESR Panasonic 200vdc 680 ohm electrolytics, temperature of the capacitors dropped several degrees as compared to brand new originals in a Megawatt.
A full scan of a "working" WFCO gave me acid reflux. Stupid is as stupid does.
Reminds me to check about black hard anodizing down here - the cheater's way to gain 30% more radiant capacity. Hello black Megawatts and Meanwells.