In fact, there is a bug with luck in 1.0.0 if I recall correct. But I was on OSI for a bit and the loot there is really worse, than on a default RunUO shard. Except bone piles and all the junk you can find, collect and sell. And the body parts are not up to date yet either. And since there is no up to date loot public guide anymore, the loot will never be OSI exact again.
So my conclusion is, as Joeku stated before:
Loot.cs
Have fun.
Then again you might need to go to all the monster definitions and change them as well. I think at least the bone piles will be droping in the next RunUO release.