Ok, been working away at my own converter. I've already made some stupid mistakes;
Firstly, I didn't remeove the pins from the bottom first. Additionally I didn't have needlenose pliers, which is pretty much essential for this job. Second thing I did was to cut the extra 2 pins off, so I've glued them back on, but I'm considering starting again with a better understanding.
Here's the data-pin jumpering (currently unfinished) using the spare ribbon cable from the PCI thing. I may have cut the ground trace, but I can fix that. I used a craft knife - will that do the trick for trace cutting?
Here's my pigs ear of a butchered PCI slot. Some pins I could't extract after they broke in half at the back, so I just bent them to the back.
And here's the other end with the 2 "extra" pins glued back on