I know it's been forever since someone commented here. Assuming his middle name hasn't been found within the canon of the show since 2005, I'm going to put out another idea.
Because of how the old-timey naming system works in the south, especially in Appalachia, I'm going to add 'Kemper' to the list of possibles. James Lawson Kemper was the Confederacy's youngest brigade commander, making brigadier general at the age of 39. He was wounded at Gettysburg, but survived to become an important political figure in Virginia. He was known for his honesty and attention to duty. Naming boys after valorous Confederate generals was once a popular practice, and if the name didn't sound like a first name, it was given as a middle name. Lukas Kemper Duke doesn't have a wonderful ring to it, but it would be geographically consistent.