So I have this 6x9 Tech III outfit on approval. Never used any Technika in 30 years of LF (or in this case small LF). Looks intriguing but one thing stymies me. I can't get the groundglass back off to accept the included 6x9 Rollex back. i realize this elegant thing is from the early 1950s but still... there are four knobs at the corners of the back, which allow the back movements/extension to move. Then on the rotating back itself are two ribbed squeeze levers, that actually allow the back to extend. But I can't find a way to get the gg back off, and replace it with the roll-film back. The roll back itself has a large round ring, obviously to allow it to rotate. I also can't see hoew to remove the focussing hood from the GG back, although there's a thumb-lever for that too. I know, RTFM, but there ain't one. I went to the review section on this site and studied Jason Sanford Greenberg's story.. but that was a Tech IV. Went to Cameraquest, great article, no details. And I thought Leicas were quirky! Any Linhof aficionados out there?