Not sure. Not a lawyer. But you should practice your boat accident story to go a long with your absent minded luck story should you be stopped and questioned.
My FIL has, for the last 10 years been driving out to AR to see his daughter, my wife. Every time he comes, he asks to store his guns at my house. A couple of years ago, he comes out and we have to go buy HIS OWN SAFE to store his guns at my house....I guess that is the best answer since he is the only one with access now.
Last year he told me to drive out and bring him ammo.....I told him no...time to pull up stakes and move to a free state. Today he is painting the bedroom in order to list it this Spring.