Duke,
your analysis on the belt tensioner from July 2005 is the best I've seen. One point that I need clarification on though is in your item #6 when you say:

"...then set the pointer at the bottom of the ramp.", and then when you turn CW that the "pointer begins moving up the ramp."

I am unclear what direction the ramp is. If you are saying that the needle moves "outboard" (to the right, vewing from the front), then is that not in conflict the service procedure (13-3420 in the M103 service manual) which shows the pointer "outboard" in the v-belt slackened position?

Can anybody shed light on this point?

My greasy hands and driveway full of parts await...

Thanks, Mark
1990 300te