You judge yourself too harshly. Only the artist can see the flaws so it's only a failure if someone else notices and right now no one can see any flaws. Therefore it is not a failure. Great work Shinpachi san.
Thank you very much, Gnomey, Geedee, Aaron and Night Fighter Nut, for your kind words which really encourage me.
Since 3D CG software can simulate various physical phenomenon like not only the mechanical movements but the luminous reflection/refraction easily and precisely, design development is much quicker than the manual drawing.
If this technology had existed during the ww2, there might have been more variation of weapons.