Well...wait for them to loot it. If they loot it: Great, they got money and the Count cannot do anything against it because he does not want to go to the authorities ("Officers! These guys stole all my stuff while rescuing me from my own creations which I created from the dead!").
If they decide not to loot it: The Order of the Palatine Eye and the Count itself could just give them more money. Or, as I said, you could throw more magic items into the Schloss which the count lets them keep out of gratefulness.
My group hat to return the rod of Flame extinguishing because the count wanted to keep it as a safety precaution in his lab. He let them keep some things he used in old experiments and didn't need anymore, though.
So this might balance it out a bit.