I can't help with the camera. But if by "lens wrench" you mean a spanner (not one of those flexible clamping things), I have some experience. I have two of the parallel bar types. One has removable end pieces, it's not the best. The other has has fixed ends, one side flats and the other points. That one works better.
But the tool that gets used the most is a pair of dividers. These are not as stiff as the spanners, but they fit in anywhere and reach deep. The pointed ends work in any retaining ring.