If it is an antique, it does devalue it if you do anything to it. You would need to get an expert opionion in that case. If you don't intend to ever want to sell it and just want it for display then there are lots of ways to repair it. From hand sewing bridal tulle over the frayed spot and missing areas,to hand sewing in vintage fabrics that you hunt for to match the fabric in the quilt. You might be able to ask at your local Historical Society? Does your public Library have a research section? You might be able to find a quilt appraiser to give you an idea for a charge of course.