This louver is on my 2008 Endeavor. There are two different sizes. The part numbers are actually on their inside lip. The mfgr is Coyote. They do not sell direct and the one supplier was not really in the business of one off's.
I suspect I am not the only person that has had one fail. I bet I get an answer here in ten minutes.
Myron & Deborah
08 HR Endeavor 40 SKQ
400 Isl, 400 HP/// Now 450 HP
2016 Ford F150 Limited V6 with Ready Brake