I'm replacing wall-to-wall carpeting with 3/4" X 2/1/4" solid t&g prefinished red oak. Floors are pretty much done. Time to do the stairs which have the same carpeting as the floors. I've pulled up some of the carpeting on the stairs to peak. The treads are 3/4" plywood. The risers are 1/2" plywood. Some of the stairs are open on one end and some are fitted between wooden skirts. The plywood treads are 10 1/2" wide and overhang the risers by about 1 1/4". The risers are 7 3/4" wide. I was planning on leaving the plywood treads and risers in place and removing the plywood tread nosing . Should I buy 3/4" thick oak treads which will allow the top step and top landing flooring to keep the same height as they had when carpeted? The bottom landing is slate which is staying. What thickness oak riser should I use, 1/4"? I will apply scotia molding under the tread overhangs and on the ends of the open risers to cover the plywood and oak edges. I have read the building code guidelines for stairs so my question is more from an aesthetics point of view regarding tread and riser thicknesses.