Not So Perfect
Part of the crooked letter/emblem issue is the imperfections of die-cast items. This is true today and it was true back when our Mustangs were new. Because die-casting isn't always an exact science, you will find occasional original and reproduction letters and emblems with flaws. Pins that are out of true will make the letter sit crooked when installed. Sometimes it's impossible to install them. Resist the temptation to redrill holes and try several letters before giving up.