as a collectible person im trying to get every unique in the game on one charecter
so my question

is there any where to get the jagged crown as a collectible and complete the imperial quest
like is there any cheats to get it so i can put it in my house ?

player.additem 000da750 1

unfortunatley im on xbox 360

I believe the only way to keep the crown is to essentially abandon the questline. I know that I couldn't help but try it on my character and run around with it for a bit...but in the end I gave it back.

In theory, I suppose you could go to the ruin without taking the quest, but I have a feeling that it wouldn't spawn for you. The draugr would, but not the crown itself as a lootable.

dam such an epic looking crown, i remember in oblivion where you could clone yourself then loot the item you wanted from the clones body
if only that was in this game

going to the dungeon without the quest probably leads you to a "needs a key" door which means your stuck.

You could try the armour duplication glitch, using the manequins. Hundreds of videos on youtube showing how to do it.