I didn't want to hijack the Chamonix locking tabs thread but I'd like to add that it is also a good idea to keep the lensboard retainers on other cameras tight as well.

I also had a lens drop off my camera recently as the tension on the lensboard retainers was not firm enough, which was my fault. After a rough hike up to an 11,890 ft peak and back down again I set up my Ebony on the tripod and my Schneider 110 XL dropped about 5 feet and hit the pavement. The constant jarring on the hike moved the lensboard retainers. Miraculously the outer lens barrel bent inward and obsorbed the shock and the glass didn't break.
Since it's prime time for photography, in order to avoid the downtime of sending the lens to Germany for repair, the decision was made to take a hacksaw to the lens! It's an odd feeling to be using a hacksaw on a mint 110XL that I hate seeing a speck of dust on!
In the 2" area of the barrel that was damaged four small cuts were made the same depth into the outer barrel as the length of the threads on a step up ring. I also cut into the lens barrel diagonally to the other cuts to make peeling back the aluminum easier. The barrel was peeled back just enough to allow a step up ring to be screwed in and the small cuts were sealed with epoxy to stop dust from getting in. The face of the newly manicured lens barrel was also filed flat so the step up ring screws on squarely.
The focus seems fine and I've been using the lens again and will ship it off for repairs during the winter.

Sorry to hear about your lens Jeffrey. I met you in Zion right after buying my Ebony 45SU and I really appreciate all the information you gave me.

I hope sharing this might help save someone's lens and the butcher job on the lens barrel is working out well.

Have Fun!