Let me preface this by saying we suck... RL got in the way a bit but we're back working on this now so here's another update!
Before we started soldering, we did a bit of a mock up of what the top would look like once it was done. We put a bit of blowhole trim round the hole for the i/o bracket just to neaten it up, and put the switches in place. So far so good!
Next we soldered the switch - it has pins for the power header to the mobo and the LED header. We cut the wires off the old power button and off the power LED and soldered them on... despite neither of us soldering since high school we managed ok and it worked first time! We tested it in my computer and everything booted up and it lit up so we put it in the case.
Next we decided to make the fan controllers. These were going to be simple: a flick switch that lets you choose whether the fans are run at 12v or 5v. There was going to a switch for the 120mm fans at the front and back of the case. We got yate loons so they were going to be quiet anyway, but since the computer was going to be living about four feet from the bed in my friend's uni room, we decided having the option to turn them down even more overnight would be useful.
It's really simple to make: the red and black wire from the fan (12v and ground) are soldered to the middle two pins, then yellow and black from a molex connector go one way and red and black from a molex connector go the other way. We tested it in my computer again, and they worked fine.
So now the soldering is done, all that needs doing is cable braiding and tranfering the computer into the new case. I should be updating again soon, and hopefully it'll all be finished by the end of the week!