I would advise reprinting that parts, round it's shape with a dowel, along the front to back axis, then do a dry fit, if not happy, then cut into manageable pieces along the panel lines. That way you can easily color any white edge black and the plane will look better for the effort.
You won't have those creases, which actually appear on real aircraft that are involved in propeller strikes, or other situations which torques the whole empennage, and cause the aluminum skin to buckle and crease. I would reprint those parts, round the reprinted flat parts with a dowel, along the front to back axis, then do a dry fit, if not happy, then cut into manageable pieces along the panel lines. That way you can easily color any white edge black and the plane will look better for the effort. Rounding pieces on any model that has a curved surface with a dowel saves a lot of time, and also shows where you may come up on papers limitation, which means the part has to be cut there, to complete fairing (smoothing) the craft. I hope that helps.