Type it out in a letter and cc at the bottom to a lawyer (esq) if you know any. Even if not, a written letter doesn't (unless you write something stupid which I'm sure you wont).
Joe who fixed and painted my Barracuda did a lot of bread and butter colision work, and also some select salvage title repairs. He told me all repair panels need some tweaking, the factory ones less, the aftermarket more. So its labor costs vs parts cost. Since they should cover the parts costs, I'd go for an original and save on the time if you can.