Recently purchased at auction an old local railroad "whistle stop". It is a 10 ft tall cement post. In the process of putting it in the ground one of the vertical edges started to chip away. Is there some way I can repair it with cement so as not to look "new". The cement is very porous with age and sorta "grey" in color. The metal frame is showing through so believe it could get a good hold. Also is there a sealer I can spray on to prevent further detieriation? Many thanks.