Yesterday I exposed the underside of the top three stairs on our
staircase when ripping out some old lath n plaster stud walls. The
stair underside was concealed by curved LnP, which I ripped off. The
underside of the stair is quite attractive, shape-wise, but the wood is
very rough and would be a nightmare to sand for painting. So, I'm
trying to think of ways to retain the shape of the underside of the
thing and what to cover it with so I can paint it. Anyone else done
similar?

tia

Antony