OK, finally got some time this evening to take some piccies. Here's a summary of the mod details:

Fan: RS P/No. 197-4558. Cost = £22.89 (+VAT). It's made by a company called ELINA. Their P/No is HDF-4012L-12LB. There's a datasheet attached to one of my earlier posts. It is a bit expensive (RS Components are never cheap), you might be able to find a cheaper equivalent.

I mounted the fan about 7mm further back than the Empeg team originally designed, so unfortunately the fan doesn't line up properly with the stamped holes in the lid. If I'd mounted it in line with the vent holes I wouldn't have been able to get the lid on. The fan would have fouled the two electrolytic capacitors on the back of the display board. The fan is stuck on with Cyanoacrylate (Super Glue). I'll have to see how long this lasts.

I looped the Blue wire around one of the main board mounting screws (see pic) and I soldered the Red wire to one of the two pins poking vertically out of the main board marked 'Fan' (as per Tony's info).

I folded the IDE cable underneath the hard drive cradle ass'y to give more clearance in front of the fan. I didn't want to restrict airflow or risk the fan chewing up the cable.

I do find the noise from the fan somewhat intrusive here on my desk. It's better in the car of course but I can still hear it if I'm listening to music quietly (so in other words I don't hear it ). YMMV. My next step is to make up a little circuit to control the fan depending on temperature. I've just got to find the Thermistors I know I've got somewhere .

I think I've covered everything here. If anyone has any more questions feel free to ask. I'll post the pics in a moment.