I have several style manuals, but I'm too danged lazy to go get them right now. I've always operated on the principle that, in case of doubt, it's best to go with whatever is the least ambiguous. If others understand what you're trying to communicate, mission accomplished.

I have been accused of writing long sentences with no commas, sometimes running for half a page, then loading a double-barreled shotgun with commas, pointing it at the page, and letting fly with both barrels.

. . . a vile slander!

Don Firth