Those little pockets can disappear with a large barrel and the right lock combination as the angle of those wood panels along the tang match the angles of the barrel.
In the case of the gun shown I would first minimize those pockets by bringing those panels down as far as the lock and side plate shapes will allow. Next I would dish out those little corners to blend them into the surfaces along the tang.
Picture to follow when get to the shop.
Jeff
Ooo, looks like that spot got neglected in the final sanding phase, but I think you can get the idea.