I've done a search and skimmed through quite a few threads but more specific fresh input would be appreciate. At any rate, doesn't hurt to duplicate some stuff periodically and hopefully there will be useful comment not duplicated already. Brief scenario: I sold a used GK 1x15 cab known to be in good working condition that the recepient claims has a frozen speaker with no indication of shipping damage to packaging and externally cab looks fine - shipped snail USPS from NC to Ohio and insured for purchase value. Mailed him the original USPS verification since he had everything else needed to file the claim and I didn't. The guy is reluctant to file a claim due to no apparent external damage but requests compensation. From what I can gather, USPS doesn't even test "whatever" for internal issues and just goes by packaging. Any personal experience, suggestions, ideas appreciated. Thanks in advance.