I recently bought a 2003 F-150 Lariat SuperCrew from my brother in law but it needs a replacement front driver side door as someone backed into it. My problem is I am trying to locate a pin striping kit in either Arizona beige or deep sandalwood (local Ford dealership wasn't really helpful on this one). I did find a kit but it says its for the right side only and that the left side kit is discontinued my question is if its just the door that needs the striping does it matter which side of the truck kit is supposedly for? Here is a picture of the truck the day I changed the rims and tires

 

Looks to me the doors would be the same.
The front fender curve is probably why it's a left right thing.

 

Agreed. Based on pic, I'd say doors are interchangeable side to side. Its just dual straight pin stripes.