It mostly has to do with keeping the piston rings sealed the the cylinder and piston. You need to measure the piston ring to land clearances. If the piston lands are loose, the rings won't seal.
If there is too much piston to wall clearance, if the rings do seal, they may wear out quickly.
If the only think wrong is scratches on the skirts, you may be able to clean/polish the scratches and maybe have an anti-friction coating applied to bring them back to size?