I have a couple old pocket knives that belonged to my grandfather. I've looked at a lot of information about removing rust, polishing, etc. I used a gun cleaning solvent with wet/dry sandpaper to take off the heavy rust and brass wire brushes. I have polishing cloths and metal polish. I got them looking a lot better, but there is some damage to the metal itself on the oldest knife. It looks dimpled. Is there anything that can be done to help with the damage short of machinery to refinish the blade or something? I'm pretty new/inexperienced so I'm open to suggestions as long as it doesn't require buying expensive tools. The knife that is the worst was from my grandfather's tackle box so it was used hard.
Honestly, this is pretty good work. The oxidation you have left looks healthy and the pitting is typical of knives that age. The bevel is straight and clean, doesn’t look like the knife is bent. For what it’s worth I can and have done full polishes through pitting like that and in a recent restoration I chose to stop just a hair after where you are.
If the pitting really bothers you, smaller blades (particularly blades in pinned knives like that) are best polished by hand with minimal tools, power tools are too fast to be precise and the pinned handles are too close to the blade to keep them safe. You’d want to mask off the handle, place the blade on a soft surface butted up against the edge of the table, handle off the table, and polish the blade with heel to tip strokes of a dowel wrapped in sandpaper, starting around 100. Once all the pitting is gone (and only once all the pitting is gone) you’d go up gradually in grit to maybe 240; where you stop is a personal preference, but it’s going to oxidize a little in the future, so a super clean polish wouldn’t last.
I would not suggest learning to sharpen this freehand. Small blades are hard and knives without locks are hard. Get a legit pro to do it (they can take out the recurve in a few minutes) or buy a Sharpmaker (which can handle recurves well). Recurves in working knives are not a big deal.