What I do is mix up glass bedding compound, and use the dye that comes with it to glue the bullseye into the stock. It fills the area around the bullseye, and once shaped and sanded smooth the repair looks great.
I also cut the bullseye stock in half, as they're fairly long, and one will fix two guns.
I also cut the bullseye stock in half, as they're fairly long, and one will fix two guns.