I not sure what You mean by original parts. Any way, You can (but dont have to) use everything, however you like, exept parts from tops, legwear or headgear whitch You can use (but dont have to) only in atypical way.
If only it will looks like somethink for warrior its ok. Most important is ingenuity.
I realy hope I speak with sens. English language can be hard sometimes.
BTW: I got extra challenge for this one. Who made a decent armor by using least number of kind of objects.