Those are some deep scratches from the looks of them. I you decide to try to fill them and/or tone them, do so before putting any oil or finish on them.
You are going to have to sand. With veneer, you can only sand so much. Again, some of those look gnarly.
I have been restoring acoustic guitars for a couple of years now. CA or super glue is a standard product for filling scratches or dings. There are scads of YouTube videos of what you can do with CA glue in restoring a finish. One creative repair is for filling a gouged out fretboard, where the wood got dry and wore away. In short, you take sawdust of different woods, like rosewood, in different tones. Scratch up the worn spot for adhesion, add CA glue, then build up the spot with sawdust. Use the different tones to try to match the grain patterns. You can use furniture restoration stain pens to add color, too. Once the CA glue is blocked down or strip-sanded, it can be polished out to where is matches the original finish. Rub in some Danish oil and the repair becomes hard to detect. Scratches can be stained with the stain pens, different shades per the grain pattern, then filled with CA glue. Overfill the scratch, then block down the high spots. Works great on guitars, since they usually have a gloss finish. Matte finish is much tougher. An sinple oiled finish will not work, unless it is something heavier that can be polished to a gloss. That said, a clear lacquer finish polished to a gloss would be stunning.
When trying to work with the CA glue, get these plastic disposable micro pipettes. Put a number of drops in a tiny cup and lift out what you need. You can find them on luthier supply sites, then order from Ebay.
No power sanders, unless you have a really delicate touch. Be careful around the edges.
Block sand. As in sand with a flat sanding block.
Wet sanding with an oil like Danish oil will cause the dust to fill open the grain in what is knows as a French finish. I never made that work. Wet sanding is always superior, just do not use water. Use mineral spirits. Again, this is how to work on a guitar, electric or acoustic.
I would love to take a crack at putting a guitar finish on a worthy pair of speakers. I am sure it could be done.
CA glue comes in different viscosities. You will need to be patient and buy online. The retail stores have limited selection and will be expensive. Harbor Freight sells packs of a heavier glue for next to nothing.
YouTube guitar finish repair videos. There are some creative folks out there.
Good luck and have fun.
