Deadly Premonition Xbox 360 Version Achievement Help

[Doom of Judgment]

So odd question to put on the forumn for the PC Version of the game but i was wondering if anyone knew about the Difficulty Achievements in Deadly Premonition, they do not stack and i have to play the game two more times on Easy and Hard, but can i just Load All the chapters with all the things i earned on normal? I sunk 22 hours into it, i completed all side quest, got all the infinite ammo weapons i could get, and even got every trading card (Including Swery) but i just wanted to know before i wasted my time with a tactic that won't work in case anyone else had some knowledge on the 360 Version.