Kurt is off to Home Depot for some wood fill and 1/4" plywood. Next weekend will be paint and whatever paper I decide on for the risers. I've already found two damaskish type papers in blue-green that would work from Home Depot but I don't think they're quite right.
Perhaps something more vibrant and unexpected is needed. Next up is a trip to The Paper Umbrella to see what they have that might work well. Too bad they are closed today! Now I want to go shopping.
Edited to add: And another option could be wrapping paper from Amy Butler? Wondering how sturdy it would be if it were varnished after application? This one is lovely and you could alternate between the three different papers all the way up the stairs.