I think I'm getting closer to solving my problem (one of my problems). I took a look at my ignition leads and they were close in places, so I separated as much as possible. This cured my pinking and my car felt Italian. It was amazing how fast it was. I think that my car's probably only been capable of about 20bph, instead of the full 39bhp. When my car doesn't pink it's really fun, but it's started again :-(.
It's not bad, but the leads can't get further away from each other, the performance has gone and it sounds like it's got a bananna stuck up it's exhaust again. I hadn't heard this noise since I replaced my plugs and leads about 2-3 weeks ago (200-300miles). My plugs and leads can't be ruined after this short distance/amount of time can they? Is it possible for my car to ruin leads/plugs really quickly (assuming all standard components)?
The misfiring noise has never gone though. However, there is a sensor (I think) in the air intake with wires which were touching the ignition leads. It has two wires going into the air intake tube, which goes into the top of the engine (I haven't really had a close look). Do you know what this sensor is? I'm thinking that maybe the sparks have jumped into it and killed it :-(
I suspect that the sparks maybe jumping to other things (such as the engine block) rather than other HT leads now. I'm gonna have a look at night to see where the sparks are going. I think I'm going to get some performance leads though, these leads are almost completely useless!