The last day I've been concentrating on work. In my free time I've been looking at extending the power lead for the battery as well as get the hole drilled for the power button.
The first setback is that the MagSafe connector pulled itself free while I was playing with the battery location and in the process damaged the plastic plug on the motherboard. The pins look undamaged but I'm yet to plug in mains power to see if any smoke comes out. All going well i'll permanently seal this up with a dab of hot glue.
The second setback is a bit more annoying. The little module with the IR sensor, power light and the little black other thing on it has stopped working. If you've been keeping track you know this means the machine thinks it's overheating or something and throttles the CPU (I.e. kernel_task shoots to 150%)
Any apple techs that may come across this and want to share their insight I'd be most grateful (I know you're watching....google analytics tells all ;)
In the meantime I'll make sure the contacts are clean and no traces are cracked and hope for the best.