Standing in Black Gold’s pit room about a week before the Austin restaurant’s opening day on November 9, Mems Davila rests his hand on the handle of Stevie Ray, one of two 22-foot-long smokers custom-made by Cen-Tex Smokers in Luling. (The other pit is named Jimmy.) The mustachioed pitmaster and former musician has been serving barbecue out of his Wünder Pig food truck since 2014, and he’s spent the past three years working with local firm 3 Fold Design to transform this former Crestview van-customization shop into an upscale barbecue restaurant with a style as sexy as the crispy bark on Davila’s brisket.Stevie Ray and Jimmy, their names a nod to Davila’s music background, power both the food and design of Black Gold. Because Davila…