Just checking - you say you've replaced damn near everything in the ignition circuit, but I don't see "put a new spark plug in" - have you tried that yet? You may get a spark when holding it against the head, but it may fail under compression, and it's only a couple of quid so probably the cheapest option available....
Now pop over to the New Members Section and give us a wee intro before some of the grumpier members give you an opportunity to explore the ways of Tom Selleck, natural water features and a tasty snack ......!