Since Lentuk and Wolf had wanted to see some pics, I did a quick demo so you can see how I do this.
In this second shot, I used a 9 sweep, 3mm gouge to cut an irregular shaped divot over the hole I wanted to repair. You could use any small gouge you have, I like a 9 sweep just because is makes a deeper cut but it really is not necessary. I try to avoid making a straight cut and if possible, follow a grain line naturally in the wood.
I then repeat the process, making this cut as close as possible in shape to the first one and save the piece that is removed. It is difficult although not impossible to match the curl if you have a cutoff piece of your stock blank from the same area. I once did a repair in a piece of maple using cherry and it ended up looking exactly like a natural inclusion in the wood.
It should lay easily into the initial cutout you made.
I use Titebond glue and tape it in place, then clamp it tightly. I find the tape helps hold everything in place on a round forearm
Let dry completely, then sand and stain. As I said, it is visible but does not readily look like a repair. On the right is a hole repaired with a toothpick. To my taste, a regular shaped patch looks unnatural. Also, the method I outlined works better if you have chipped out wood, which you often get in restoration work. Hope this is helpful to everyone.