Mass Effect 3 Regular to Mass Effect 3 N7 Collector

Hello there, I just did a whole playthrough with regular Mass Effect 3. I wanted to have access to all my N7 Collector edition's goodies, so I bought the game for the fourth time, and second time N7 Collector edition. Now I just imported a save game from my old game, finishing-it with the new one and importing-it to have access to the N7 weapons and everything. Unfortunately, being on mars right now, I cannot access my N7 weapons (at the Mantis pickup point), they are still locked. Am I obligated to go through a new game all the way in order to access these items? Is there a way to avoid that?

Edit: this is on PC.