The removal of old staples and nails without damage to the wood depend on leverage - pulling out seldom works and, speaking for myself, my pulling power with nails rode off into the sunset along with my pulling power with women, too long ago to remember
The small flat bar I mentioned will to, but, at a pinch, the blade of a large screwdriver laid flat on the floor will suffice
I spent a great many years easing up old floorboards for my work - an interesting occupation sometimes, especially when I rolled back the lino to find the floors covered with old newspapers in almost mint condition (an ols method of preserving the floor covering)
I spent an entire afternoon on my knees in the upper rooms of a pub in Vauxhall reading about the outbreak of W.W.1.
Jim Carroll