Hi Michael,
My 14-13 had a box like structure made with an upholstered piece of plywood or metal with a padded, hinged top for an armrest. I still have the pieces to re-do and install, I think. Yeah, it did add comfort and convenience, so it should go back in. I don't actually know whether it was original or not. Flip the armrest up and rummage for the sunglasses or maybe a cardboard calculator to see what my TAS was. Very practical.
ron marks