Well. Here is what I would do if it were mine.
Spoiler alert! A bit more work, but imho totally worth it.
Grab either some oxalic acid (wood bleach) or deck cleaner and clean the hell out of it and hit it with a pressure washer.
Once dry, plug the holes with dowels and resin. Then sand it with some 120 and glass it over.
It will be beautiful.
GT