I haven't been able to feel the 2 resistances as you described Tomo but I went ahead and put some petrol into the spark plug hole to see if it would fire up. I pulled a few times and nothing happened but on the fifth pull there was a small explosion, maybe I put too much petrol in. I thought good sign, at least something is happening. I then put more petrol into the spark-plug hole and after pulling on it about 10 times it started up and ran for a few seconds. There's still work to do on this but I'd like to know a few things.
1) I tried to adjust the timing the best I could, the fact that it took a number of pulls to get it going, does that suggest that the timing is perhaps not quite right or will it not start if the timing is out?
2) There's not much of the snorkel left and therefore plenty of air is getting in, would that have any effect in starting the mower?
3) The photo above shows how that instead of the conventional spark plug boot there is something resembling an electronic spade terminal, can I stick a screw into the high tension lead (what size?) and get a spark plug boot for it?