It's beautiful. Check with your local quilt guild to see if they can hook you up with a person who does quilt appraising. They usually charge a nominal fee. My quilt guild had an appraiser come to judge a county fair and she gave appraisals while she was there. Your quilt won't have to leave your sight.
Please remember that plastic bags keeps moisture in. If it is stored lets say in an attic, the heat would cause moisture to bead on the inside of the bag. It could ruin the quilt.