Are these floors worth refinishing?

Hey Reddit community. I pulled up a thin wood veneer (nailed every 6inches…) in an 1880s house in Chicago and found what appears to be the original floor underneath it. I’m not incredibly sure of the species but it does seem like a hardwood (red oak would be my assumption), but the tongue and groove boards are 3” wide which makes me think it’s some really hard old growth pine. Have others in a situation like this, with nail holes and nickel sized chunks of wood gashed refinished their floors successfully? I’m seeking Reddit opinion before I just buy some new flooring to put on top of this..