Matt, take that lock apart and leave the comb wheels out. Put the dial and drive cam wheel back on with the spline key. Rotate the dial left and then right. When going left the lever drops into the driver and is pushed back up. But going to the right the driver to lever engagement soon stops dial rotation at full bolt retraction. When the lever nose drops into drive cam, note the tip of the fence drops down and rests on the part in question. We'll call that part the "fence/lever retainer" for lack of a better name since that is its job. If you had the proper change key you could insert it into the little hub which is pressing against the spring leg of the retainer and rotate it 1/4 turn right. This allows the retainer to bend upward which in turn holds the fence tip up. And when you rotate the dial left and right the lever nose does not drop down into the driver, allowing the dial to rotate to the left as before but more importantly to the right without being stopped by the bolt lever. At this this point you have isolated one of three functions of the change key as it does its job. The other two functions are 1. , to stake the outer wheel portions immovable as the key is inserted into the lock and 2., to release the inner wheel sections from their outer sections as the change key is turned that 1/4 turn we already made. Clear as mud huh?