Question:
On Saturday I opened the door to my TJ to find that my fire extinguisher had discharged overnight! the entire interior was covered in a white powder! I couldn't believe what I was seeing. It took me 3 hours with the shop vac and other cleaners to put it right again. I had the extinguisher strapped to the sport bar and there was an o-ring that popped out at the neck. Moral of the story: Don't buy fire extinguishers from Canadian Tire.

Answer: I wonder if there is a place where one could buy some of those plastic twist locks which could be used to secure the O-ring and pin. Such locks are used to lock cabinets, utility meters, etc. We use them in the ER to lock drug cabinets and "crash carts" for inventory control. The locks can be twisted open quickly for immediate access in an emergency. The metal version of these would also work, but may rattle more.