I just watched your video at Reddit. Though the F mark isn't clearly visible from that distance, it the light comes on immediately as F aligns with the pointer then it is correct. However, the gap is also important and we can't see the points plate position which would have an effect on the gap of the points - smaller gap, light comes on later; larger gap, the light comes on sooner, so the plate is supposed to be rotated to the position where the light comes on at the F mark WITH the points gap between .012" and .016".