Is my old hard wood floor worth selling?

One man's rubbish is another man's treasure, Facebook is a popular place for selling nowadays if you have that or a friend that can post it for you. People are always on the look out for a bargain so would expect it to sell quiet quickly. Set a price and haggle to get a result hopee that helps

Old hardwood is always useful to someone. Place a add on Facebook either free to collect or a minimal fee.

If the old floor is on a locking system the likely hood is it won't go back together, if glue was used in the joints then it would need sanding off again damaged joint personal i would cut my loses

It all depends on the quality of the wood flooring as it is now , when wood has been exposed to water damage it tends to swell even if not noticeable to the eye so refitting could be a problem for who ever buys it so make sure you state on your sales receipt sold as seen to avoid any come backs on you as the seller