That means Cletus is likely from somewhere on the threshold of Middle Tennessee and East Tennessee meaning different parts of the two distinct regions rubbed off on the family. Also a quick google search shows that only four states had people with the “Spuckler” surname (not sure how reliable this is) Texas, Tennessee, Florida, and Ohio. I think if forced to pick from one of these TN is obvious.
Very good research and reasoned arguments!
I thought of Mississippi, but that seems to be obviously wrong.
The logic behind my assumption lies in the fact that their daughter Mary made it to New York and Hollywood, which reminds me of rural Mississppi-born singers that made it big in the entertainment industry, such as Britney Spears, Brandy Norwood, La'Porsha Renae (all of whom happened to be born in McComb), Elvis Presley, or LeAnn Rimes.
But on the other hand, it would also resemble Dolly Parton's course of life, which would support your thesis.
Can you detect a distinct type of accent from their mode of speaking, or can you identify their local vernacular?