It's not an hour long task dude. XD You need gold on all of the weapons in that weapon class. Ie The snipers class, you need all the snipers to have gold camo to unlock diamond.
Same with all the other classes. It won't be easy! XD.
If you want diamond snipers then you need to get all 4 snipers to gold then you have all 4 snipers in diamond too its really hard to get too I have diamond snipers and they are the easiest because there are only 4 but there are like 15 assault rifles and that is hard.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.