Circa 1830 farmhouse. Staircase bannister is split diagonally half way up the open staircase causing, of course, the entire bannister to wobble when used. Cannot identify the type of wood. Bannister is a round piece of wood, only flattened slightly on the top due to wear. I need suggestions on how to repair without completely dismantling. Bannister supports two spindles per stair, which are in very good condition with no cracks or splits and there are 13 stairs. Can anyone help?