When facing the 1960 version, use energy weapons. Standard bullets will only do minimal damage on its armored parts. Try firing a fully charged LaserKraftwerk and connect all its lasers. You can also use the Assault Rifle in dual-wield mode with its under-slung rocket launchers to do significant damage. Fire the Mount Machine Gun if you need to save ammunition for other weapons. Charge up again when its energy gets low and repeat.