When the contractor installed the treads & risers he left a gap between 3/4 & 1" on both sides. Treads/risers are 1" thick (actual) and tread has a bullnose front. Length of the run from top to bottom is 15 ft. Tread is 10 1/2 inches and risers are 7 1/2 inches. There is a baseboard made of 1x10 already in place and want to seal off/cover the gap that exists. Distance from bullnose to top of baseboard varies & is between 3 1/2 & 4 inches. Distance from back of tread to baseboard is just at 10 inches. I've examined almost every possible method and can't come up with a solution. One online website suggested caulking & painting; but that would take over 3 tubes of caulk to fill in from the stringer to the top of the tread/front of the riser is of course 1 full inch deep. Any suggestions?