A hand-painted sign greets you at Whup’s Boomerang Barbecue in Marlin. (Photo ©Chris Wilkins/Texas BBQ Posse) Our first view of Whup’s Boomerang Bar-B-Q in Marlin brought back some nice memories. We hadn’t seen such a genuinely classic-looking joint since our last visit to Pat Gee’s in the woods east of Tyler. While Pat’s is nestled among pine trees and pasture on a rural road, Whup’s is on a thinly settled residential street where the edge of town invades the country. A hand-painted sign – the Posse loves hand-painted BBQ signs – greets visitors to a small building that has been…