If you want I could also loan you my distressing chains and punches - Just kidding
One person mentioned a woodputty... Here are some more "ideas".
Some wood putties tends to lighten in sun while others that are oil based tend to leach the oil into the surrounding wood sometimes making for a visual mess (kind of like a halo). I have no idea how to fix the halo. But, on the ones that lighten, they make furniture color felt tip markers. My wife uses them from time to time and they actually work quite well.
If you have some veneer that has cracked or split and has lines try this. By using the same species along with the same finish material the outcome will look like the darker portion of the wood grain:
Get a piece of same species wood. Sand it using a sander that has a dust collector on it. After you have plenty of dust take an appropriate amount of it and blend it with the same finish material that you use to varnish the wall (or surface). Once you get it to a thick consistency (just a bit thicker than epoxy peanut butter), using a putty knife, trowel it into the crack. Make sure you trowel it such that the filler material is just higher than the surrounding surface. (I wish I had a picture I could upload) there should be a raised line where the crack was and there should be no or very slight amounts of the putty on the original veneer surface. Once it dries sand it down with (I like) 120 and then finish with 220 grit. Be very careful when sanding because if the surrounding veneer is the 1/60" thickness you will sand through VERY easily.
Ever have someone drop a heavy object and nick the wood? Steam it out. What happens is that when the wood is struck, the cellular walls crush and the wood compresses. Take the area that has the dent and fill it with water (not the whole surface, just the dent
and let it sit and absorb. Then using your clothing iron (NO water in it to create more steam) place a towel over the dented area (so you don't burn the surrounding area or melt the finish) and heat the water in the dent until it's gone. This pushes water into the cells and causes the wood to expand. For small dents you may only have to do it a couple times. I've brought out dents that were 1/8" + deep but had to do the steaming maybe 7-8 times.
Although I've never used them, they also make a colored filler that is melted into place. But from what Ive seen you need some special tools and a lot of practice to get a good color match and you still are left without any grain.