Recently made a fireplace surround from a reclaimed, hand-hewn white oak beam. It has been sanded but retains a nice gray and brown patina that matches the flooring and stone surround very well. Any suggestions as to what would be the best topcoat without darkening the current coloration? A satin finish is preferred. I tried Waterlox, ArmRSeal and Endurovar on samples with Endurovar providing the least color change. Wax could be an option but the roughness of the handhewn edges would complicate that a bit. Thanks in advance.