Rev. Rul. 56-488

Where an article subject to the retailers excise tax, owned by a customer, is lost, destroyed, or stolen while in the possession of a retailer, the replacement by the retailer with a taxable article constitutes a separate and distinct taxable transaction. In such a case, the retailer is liable for reporting and paying the tax on the basis of the monetary value of the customer's claim against the retailer for the lost, destroyed, or stolen article, plus any additional amount paid by the customer. If no monetary value is ascribed to the customer's claim against the retailer, then the basis for the tax shall be the usual retail sales price of the replacement article.