I've shipped a lot of antiques over the years, usually smaller than rifles, some larger. Never had one lost of broken with USPS but seldom shipped long rifles. The one that did break was poorly packed by the FFL, and they used UPS. When my gun shop FFL called me to get it, they showed me cracked wrist and broken rear sight. They recommended that I "refuse taking delivery" from them, the gun shop. I did, and after a few weeks of the UPS insurance claim, which I had to manage, I got a big settlement check that almost paid for the rifle. Got a sight and new stock for very little money, pocketed the rest. Insurance is for just this type of thing - broken or lost in shipping. Insurance premiums are the percentage you pay based on YOUR desired value. Within reason. They should not require an appraisal after the fact. But if they do, I'd have a friend pencil whip on up. Then they can argue that "he's not a legit appraiser" or whatever they try. Just keep plugging away, you will eventually get your payout. Their job is to wear you down so you quit.