So I finally got around to ordering the new PSU for the Gateway, went with a used original alternative to the one fitted - an Astec 200W with the same unusual shroud and non-ATX mounting holes. So long as it doesn't smell like the current Powertech and works, I'm happy for £11.
Also ordered a whole bunch of fans. 2x 60mm Gelid for the AMD stock cooler in the other machine, and the Voodoo 3 card, and 80mm and 92mm case fans for each respectively.
Was faffing around last night trying to get the front LEDs on the desktop case working with the ECS motherboard. Managed to get the HDD activity LED working but no look with the power LED. Even tried swapping the LED cable out with a spare I have, no luck. Must be an odd motherboard with a wierd pin arrangement.
Taking inspiration from the recent LGR video, I may attempt to plasticoat both of these cases in an attempt to cover over the various marks and scratches I've been unable to rectify.