I’ve refinished numerous hardwood floors over the past thirty years. The main thing to come to terms with is that the imperfections in a thirty year old floor is part of its charm. It will never look like a newly installed pergo floor or anything like that. Even a complete sanding refinish won’t make it look like a modern floor. It’s a decent amount of work to completely refinish too. And all that does is steal the charm away.
What I recommend for old floors is to first go through and make sure all planks are stable. Any creaks can be taken care of with a new flooring nail applied at the right spot. Then clean it with a mild soap to prepare for the final finish.
What you want is a good quality hardwood paste floor wax. Goes on thick and is best applied with an old style cloth mop. It will make the floor absolutely magnificent. It looks better than any new floor you could possibly install. It’s just stunning.
BWC has everything you need. If you want to hide or fill in scratches, then use the New England Brown Wax, assuming it’s not to dark for your floor. If you want to keep the original color, and just ad incredible shine, Clear Paste Bowling Alley Wax will do the best job. Very durable and long lasting. Don’t get a liquid… make sure it’s a paste. Renaissance works well too, and a little goes a long way.