Selling Abandoned Jewelry to Satisfy Repair Costs

[bikin909]

I own a jewelry repair store in Missouri (St Louis). Before repairing any jewelry, I have the customer sign a waiver stating that, among other things, jewelry not claimed within 30 days will be sold to satisfy the repair costs. Several customers have not returned to pick up their jewelry (after several months), even though I've called and sent them postcards.

I'm hesitant to sell it, for fear I'll get sued. Does anyone have advice on the best way to recoup my costs while minimizing my chances of getting sued?

Thank you in advance!