I know several Bomber Command trophies 'disappeared' from the Mess and were eventually relocated in the AOCinC' s suite in the HQ.
Echoing others, I was house member at Wittering and started an inventory of the silver. First thing I discovered was a lack of shelving in the store. I took my Swiss Army Pen knife !and dismantled a section of shelving from the drying room. Staff were horrified but no one else noticed and we had 50% more shelf space
As the Mess was now home to the Harrier they had stashed a couple of large oil paintings of a Victor and Valiant to a store room. When it was pointed out they were Shepherd's valued 40 years ago at a conservative £5000 they were brought put again.
As said, insurance is a significant factor.