Thanks for your detailed explanation -then a question.
I really appreciate the pics of your timing chain surgery. It gave me the stones to open mine up to check for slack. Some weekend when I have more time, I'll do the rails and the tensioner on mine.
I did have a question about the stretch reading:
With the valve cover off, and the hash marks lined up on TDC, my damper reads right at 0 degress maybe 1/2. However when I totally relaxed the breaker bar and 27mmsocket, (actually it might have backed up a bit it slacked back to 8 or 10 degrees. Too much play to just ignore. Would you supose a correct reading would have the chain tight or should the slackened reading be the telling one?