Thanks Ted.
And you're right. Initially both Doc and Chet did assume Merle was using more than thumb and index. Chet thought there were 2 guitars! when he first heard some of Merle's recordings...and tandrink I believe you're right about Ike Everley. (Brother Fielding I'm sure can add a few more details when he sees this thread.)

I'm thinking of the video put out by Smithsonian (with Pete Seeger doing the interview) (still available through Homespun) and Pete does mention it can take a year or longer to perfect the damping technique which obviously Doc has got down stone cold. It took me several months to get it to sound right, as the touch is very subtle...and some days you've got it and some days you just don't. *G*