So I'll put my hands up and come clean, I've been trying to get hold of FSP500-50FSPT for some time to make them available in the UK. I also noted iFreilicht's work on providing the missing -12Vdc supply rail, a very competent circuit that has been succesfully tested.
From my own background I saw a slightly simpler, quicker way of providing the -12Vdc supply by using a DC-DC converter. Maybe not as cheap as iFrellicht's raw components, but quick and efficient to deploy. Depending on how much power you want available on the -12Vdc rail depends on what wattage 5 to -12V dc dc converter you use.
*slightly out of shot but the -12V blue wire of course has a molex pin to slot into its spot on the 24pin connector next to the orange 3.3V wires.
I've simply used a 2W unit which is going to give you a max of 0.16A, not a lot but enough to provide the reference voltage if needed for POST. Which plugs in to one of the molex connectors and feeds in to the 24 pin connector. The size of the DC/DC is approx 20x8mm, small enough to be able to be cable tied to the 24pin ATX connector cable loom without being to obtrusive.
Here is a link to FSP500-50FSPT with options for the above.
I've tried to follow your forum rules and hopefully this is helpful to someone here.
If it is deemed as not helpfully, please do let me know and do feel free to remove this post. thanks
