You may in for a surprise with that flat paint...
Fire it up as is... then season it up and rub it down with bacon fat.
Will bake in and harden... leaving you with a weather-resistant gloss sheen!
Custom Klose Backyard Chef... of Snot, and a 22.5 WSM
Lang 84 Deluxe kitchen, Lang 60 Mobile - The Damsel II, Lang 48 Patio - The Damsel, Bubba Keg Grill - RIP, Double Barrel Smoker and a BSKD