How desperate are you ?
You could go on Ebay and buy an unopened Hardened Edition of MW3 - in it there will be a code that will make you an "Elite Founder" and then you would get all the DLC and Winter Camo for sure. Most people are still not 100% sure how they got Marine Camo - I still think its release was a glitch during a game update.
But I do have it and I am an Elite Founder.
Who got Marine Camo seemed pretty random - some got it - some didn't - didn't seem to be any pattern or good theories on why.
The only theory I heard people repeat a few times was that they had made changes to a class on Elite and then pushed them to the game - and suddenly they had Marine Camo. Then I saw a few people that said this didn't work for them.
I have no clue. I've tried everything I've read and seen so far but never had luck. It's kind of angring since my friend tried the same thing as me and got it in his first trie.
hmmm im not that desperate, this is my first ever cod and im kinda late on these type of things but thx so much for your reply.