Just measured and the lock cylinder itself is 22mm wide. The black rubber/plastic seal surrounding it is 34mm wide on the outside and the inside surrounding the lock cylinder is about 1mm thick so the trunk opening should be around 24-25mm wide. A 22mm camera body should fit snug in the seal but the cameras come with an outer seal so the one on there might not be needed....still 22mm should fit.
Found
THIS one with a body diameter of 22.5 which should fit but I don't trust the metal tabs to keep it there in the long run. Especially with the thinner neck near the lens and no seal.
Then there's
THIS one with a 32mm outer diameter which would be good for the 'look' since the original seal is 34mm. But the body diameter of 28mm would require some trimming of the opening.
Maybe I'll hit Fry's tomorrow and see what they have if I can't find something else that'll fit without modification.