Several things Uncle D.
First, the centre screw is correct for the brass type.
Second, on any anti-clockwise drive K2F the upper cam lobe fires the pick-up next to the engine, the lower one fires the one the gearbox side. Which goes to L and R plug is up to you when you time the ignition.
Third, I also don't think those teeth are meshing deeply enough, but could just be the pic. If in doubt, hold off running things until doubt dispelled, as the teeth have a habit of stripping.
Fourth, the variation in gap is too big.
Rather than join Berger at the pub (it's shut now anyway!), you could try loosening the screws that hold the camring housing on. Wiggle it a bit and retighten. You might be surprised.
If OTOH that does nothing useful, you could take the screws out again and take the whole housing off to see whether the race for the bearing looks central and that there is a decent insulator washer behind it. Poor seating is a common reason for error. If the outer race comes or falls out of the housing easily, that is bad. They should be buggers to extract, needing gentle heat and a careful line of attack.
(Am assuming there is no up and down or axial wobble on the armature due to wear or poor assembly, with everything screwed up tight. Also that the camring isn't loose.)
You could also fit a different set of points if you had one handy, to see if the problem persists.
The cb will come off in the end - wiggle and wiggle some more with the centre screw, the needle-nosed pliers or whatever..
(Generally speaking, any wobble in rotation of the cb unit on the armature will affect both sides the same. You could waste a lot of time trying to make it turn as true as you like, without solving the gap variation problem. Getting the firing interval between sparks correct on a K2F is one of the hardest jobs.)
