How could I avoid halo around the nearest and furthest edges

[Oleg Volk]

Six images done with 100mm lens at f11. The closest edge was replaced manually, but you can see the halo effect around the buttstock. How could I get rid of it without retouching by hand?

Settings: sharpening 4, smoothing 5(I think, whatever the default is)

[Ariel]

More Radius and less Smoothing (I think; it might be the opposite) results in less halos.

[Dan Kozub]

I would suggest to add background with fine texture if applicable.