It is important that if you use the epoxy method that you match the colour of the stained or finished wood. The paste made from the epoxy will (most likely) not absorb any of the finish so you need to match it not to the prefinished wood but the finished product.

You can go to a hardware store and buy a plug cutter. With this and a sander and a lot of patience you can cut a plug so the grain matches your bow. Try going to you local lumber store to get a scrap peice of wood that is of the same type as your bow.

My 2 cents
Eric