Scale and Mounted Weapons Question

Here is something I have been struggeling with. When a character is using a mounted weapon on a vehicle, which scale modifier do they use then shooting at different targets. Here is three examples:

1.) A gargantuan space ship (+6) with large (+2) turbo lasers operated by a normal WC shooting at a huge (+4) spaceship. Does the WC get -2 (gargantuan vs huge), a +2 (large vs huge) or even +4 (normal vs huge) bonus/penalty on his shooting roll. I could see valid arguments being made for all 3 scales.

2.) A deck gunner on a pirate ship firing the ships cannon. Both ships are huge, but the gunner and his cannon are normal sized. Again: +4 or +0? Here the argument for normal scale on the shooting roll is much stronger, since the interaction with the weapon is more direct than with the electronic controls of a turbo laser in example (1)

3.) A jeep with a pintle mounted machine gun. Is his scale based on the jeep (Large +2) or Normal (+0), because he is operating the weapon by hand? If it is +2, then how is this different from firing the weapon when it is mounted to a barricade where his scale would definetly be normal (+0)?

Your input would be greatly appreciated.