Yeah man your are right. Merle learned from Mose Rager. They both used only the index and thumb to play. The also used thier thumb noting and muting the bass strings. They called it "choking" it. People around here still say "chokin' the box" and that goes back years to the early thumbpickers. If you are chokin' the box you are useing your thumb to note and mute the strings on your guitar (or box). Thumping it is another term used alot around here. Mose flat thumped that thing. He had a thumb lick like you wouldn't believe. Merle a hard one as well but Mose's lick was big. Mose didn't alternate on the bass strings though. To the best of my knowledge none of what they call the 4 legends (Ike Everly, Mose Rager, Arnold Shultz, and Kennedy Jones) alternated on the bass strings. Merle created the appearance of alternating by working his thumb to hit his (let's say for example) Big E string noted in the 5th fret and then open giving an A note then E note. He did that alot. The old timers before Merle didn't alternate though from what I have ever heard. Now the pickers that learned from teh old cats have incorporated all kinds of techniques through the years. When they get really traditional with it or play one of the really old songs they will stop alternating most of the time. Rarely do they go back to just the index finger though. When I started playing guitar that is how I was taught was just the index finger and thumb. Of course the heavy mute on the bass strings (something I still do to this day). I learned my forward rolls and everything with just the thumb and index finger. Now there is no way I could hit them like that because I got away from doing them like that so long ago I have lost the touch. Merle played them like that his whole life as did Mose.