On the photos below, you can see that the white marks are on a scale that reads "before", then counts up 2, 3, 4, 5, and then goes back to 4 again! Then it reads "after"
The white lines are marked against "5"


I know that the static timing for USA cars was 5 btdc static - is this what this is? But why does it then go back to "4"? BTW, my car is definitely not a USA import, and has the original UK engine.
When I use my timing light, I see the 2 white marks - if they represent 5 btdc, should I advance another 5 degrees to get to 10 btdc?
There is another single white mark on the damper, which I thought must be a TDC mark, but it's a long way from these 2 white marks, and I can't see it on my strobe even though I've got an advance strobe so can dial in the 10 btdc I believe the car is at. In fact, I can't bring the single mark into view no matter how far I turn the advance dial in either direction
I'm probably being thick as usual, but .......HELP!



