Carpentry and Woodworking - Finishing Sides of a staircase

I Recently turned a staircase in my house. The stringers are on the edges of the staircase with no support in the center (i have no idea if this is correct or not) so after turning the staircase I decided to replace the old treads with oak and oak risers, now that is done but the edges of the treads and risers are leaving small seams at the ends. My question is is there a way to neatly cover the small gaps at the ends of the treads and risers? I suspect I will probably be routering out a reverse pattern of my staircase but have no idea how to create a template or pattern to follow ( I would like to do it out of oak and would definatley not want to mess it up as of the cost).

Thanks!
bob

There is a trick on exposed ends of returns, but you have to do it before you install the treads. They must be cut about 1" longer than the stringer , and the 1" trimmed off except for a 45 degree angle starting at the long side of the bull nose and ending at the 1" cut. A scrap bull nose is then cut with an opposing 45 degree angle and attached to the side of the tread, making it look like it was banded with the same material. Routing the edge will give less than perfect looks to the end grain. My method will hide all the end grain. All your risers would be returned in a similar manner, exposing only long grain. Also, you need an additional stringer.