So often people get screwed up with vacuum advance and centrifugal and minor carb issues because they dont really know the reason for something ,,,they are just guessing. I have seen this even from seasoned pro's and mechanics. Thats why I was skeptical to look at your article at first , but when I read it, its obvious you have a good grasp of those things. Once you have that, you can fix about anything because its just logical deduction from there. Good article !