Hi Tedd
Something close to this situation has happened to me in the past. Here is how I feel about it. If the customer is a good customer refund the money for the missing items, good will goes a long way with good customers. At the same time try to process the insurance claim , but this will be hard unless the customer noted, documented and complained to their carrier that the box looked tampered with. Ebay protection police will either make you take the loss or the customer depending on how they interpret the claim.

Wayne