Wait, two arrows? I don't even see a second arrow on the outside, just the inside (which isn't visible when the mode switch is actually fitted into place)

See attached photo and please refer to Posts 2 & 3.

Sorry for taking almost a week to respond...anyway, I have a noticeably different arrangement, and there aren't any missing parts in case you were curious. I cannot find any obvious timing marks to match the little arrow to.

Yes, a different arrangement. There were at least three production years between yours and mine.

As I have no service data, and too many years have passed, I'll have to bail on this.