M.P.
Unless this is a high quality chair that will be used for years with the possibility of being used by grandchildren or unless it's important to you to have it look like new, I'd either sand and paint it or use it as is. Assuming it's structurally sound. I suggest that unless it's a highcend chair and you want it to look really good you buy a new chair. The cost of supplies would pay for a new chair. Then add the labor. Would you enjoy stripping it, sanding it, steaming out or filling in the dents? If so, that's a different story.