Wall safe jewelry

On one of my explorations of Burthorpe I came across a trapdoor behind the bar in that town. Being of an adventurous disposition I lowered myself into the hole. When my eyes accustomed to the dim light I found to my surprise three men running a rogue operation. In the middle of the cellar there is a place containing four wall safes that you can try to break into. Now what I would expect is the odd piece of jewelry and personal items like dice and portraits. What I found most of the time is some coins and other than that only uncut gems. This leads me to wonder; who places all the loot in the safes for the people who crack them and why are there only gems and not some other things like rings, brass necklaces, portraits and pieces of string? It would make the experience much more realistic.