Interesting point to add to Walters comments, depending on load and RPM I have seen the actual spark with a 6 degree lag, but at typical cruise it is in the 4-5 range, so it should be noted that the numbers are always dynamic and one should not get hung up on a "fixed number" state of mind.
I suspect you are right Lumpy, option A is likely, old guys like Walter might know better. And when the independent mag came along nobody would have had reason to give it a second look would they?