I know very little on Ithaca's, but using the rotary bolt that is used on the L.C. Smith, if the spring loaded detent is pushed down, the top lever will move past center to the left. It will go farther because as Chuck stated, the barrels top rib entension is not there to stop it.

Why the top lever moved to the left upon removing barrels could be that the spring below the detent is broken and not letting the dedent hold it's place on the rotary bolt and to hold the top lever to the right

David