After 110 years long term durability should not be much of an issue. It all comes down to esthetics and personal preference of the buyer. You are targeting an educated buyer who knows and understands the limits and beauty of both damascus and twist barrels. The one which looks best will sell faster if all other things are equal. Easiest thing to do is list both for sale and keep the one which does not sell first, if it is all the same to you.