Metal Marines happened in 1993.

Metal Marines was created in 1993-12.

You have to take 4 photos:

Front

Front Right

Front Left

a Close up of the Marines Mark (Located on the right of the Metal Gear)

Sneak past the marines and go to the front right (North West of the metal gear)

Equip the camera and take a photo

do this for the front and front left too.

For the Marines Mark go to the front left and then keep going as deep as you can inside that room. Face right and there you see the marines mark. Take a photo. Thane go to the computer which is located in front of the right door and press triangle.

Have fun :)

Yes

The collective noun is a muscle of marines.