Works perfectly - excellent! :)
For SGI Fuel ATX Power Supply converter - NEW VERSION!
The converter arrived very quickly, and was well packaged in plenty of bubble-wrap in a sturdy envelope.
There is no documentation included with the product, but the link to the descriptive PDF is on the product page, which is equally convenient.
There are small discrepancies between the documentation and the board I received (the LED colours appear to differ, for example) - but I didn't have any major issues.
On the plus side, the converter worked and my Fuel is up and running again!
I used a Corsair TX650M semi-modular PSU, and found the only issue to be that the (single) cable with molex connectors supplied with this PSU was slightly too short to be able to swing-out the Fuel's drive-bay. I may use a spare cable from a different modular PSU to hook-up the optical drive, once I've confirmed that the cabling is the same.
Overall: Brilliant!