With the aid of the trusty dremel I have cut the hole in the bonnet for the air filter sausage to poke through. Unfortunately it isn't exactly right! It just needs a little fettling and opening up, particularly on the offside side. It's better to have it too small than too large I suppose although it's a bit of a pain as the cutting needs to be done at the house and the fitting at the garage (an 8 mile round trip in total!)
I've been directed to a friendly MOT man in a local garage that could help me through the MOT. It'd be good to get the car a once over anyway before it hits the road.