Dayn Perry of CBSSportsline.com dug up this gem.  Yes, it’s Hall of Famer Johnny Bench on Hee Haw, singing covers of Jim Croce and Jerry Reed(!) to the delight of the Hee Haw Honeys.  Pay particular attention to Bench’s trousers, or as Perry calls them, “Aquaman pants.”
Bench must’ve been on the show more than once, because here he is (in maroon pants) with a glorious mustache, clowning around with Junior Samples.