Which I'm guessing will be the electrical, and with Andrew, you're in very good hands!
Thanks for the compliment-I only hope I can live up to it! Boxing Day morning, a decent coffee and a mince pie-here goes.....
I've no idea as to how much mechanical knowledge you have, so I'll start at the beginning and you can skip the parts you know already! I'm assuming the starter motor can turn the engine over satisfactorily, as we'll need that later!
For the engine to work you need 3 things: fuel, oxygen and a spark. We've ascertained we have fuel, and it's unlikely the air supply has gone wrong, so let's investigate the sparking side of things.....We need to confirm there is a spark at the plug first, and this is easiest done by removing a sparking plug from the engine & looking for it! Remove the H.T. lead from a plug & unscrew it from the engine block. What colour is the plug? Grey and clean is good, black and sooty is bad, suggesting a weak or non-existent spark. If the plug needs cleaning clean it up or use a new plug for the next part. Reconnect the H.T. lead to the spark plug but DON'T screw it back into the engine block. Instead, rest the plug on the engine block, ensuring there is good metallic contact between the plug and the engine block. You might need an assistant for the next bit.... Ask the assistant to start the car while you look at the spark plug on the engine block for a blue spark. You SHOULD see a blue flash between the electrode and the tip of the plug every time the plug sparks. If you don't, switch off and make SURE the plug is earthing out on the engine block. If you're sure it is, and you're STILL not able to see a blue spark or flash, H.T. current isn't reaching the plug, so it's time for stage 3....
If you're unsure about this or not confident to do any or some of these things, don't try it! It's better to leave things as they are than to have to remember what you unscrewed, adjusted, unbolted and changed after you've done it & you're confused!
Barnet to Slough.... Not the end of the world for a "road trip"....