Thanks for the tip Newt, and thanks for the explanation OldMan.
News from the alignment front...
I got a set of long ball end allen keys today and with the help of a few bits and pieces to bodge together a rudimentary lever. I didn't even need to cut off the bend so I still have a complete set, which is a bonus.
I've managed to get the blade from being about 1mm (0.04ish inches) out to being about 0.1 to 0.2mm (something between 0.004" and 0.008") out, which is about as close as I can see myself getting it without a more accurate way to measure. It's visibly straighter and measures much closer than it did. All I need to do now is throw some wood at it (after a quick run-in as suggested by Newt) and I'll finally be putting my new toy to some good use.
It turns out the 4 allen bolts were the ones I needed to loosen to align the blade. It actually gave a surprising amount of movement.
In the end I used a couple of 5mm allen keys to hold the blade equidistant from the table while I tightened up and it worked (almost) perfectly.
Thanks a million for all the help in this thread. Now I just need to come up with a way to replace the bar on the mitre gauge to get rid of the slop, make a few new toys to use with it (jigs and the like) and stick a new blade on it and I'll start knocking together a review of it.
BS