The Mechanic on Dukes, was indeed Cooter, Cooter Davenport
It seems as tho the search for Who Cooter Brown is a popular one.
I copied this from http://www.word-detective.com/
Dear Word Detective: When living in Mississippi, I occasionally heard the following phrase descriptive of total inebriation -- "Drunker than Cooter Brown." The phrase was used by both Blacks and Whites in rural, southern Mississippi. Who was Cooter Brown? Why was he such an (in)famous drunk? -- Chris Wells, National Wetlands Research Center, Lafayette, LA.
This question is enough to drive a fellow to drink. I don't know who Cooter Brown was, or why, if, when or where he was such a famous drunk. Haven't the vaguest, in fact. But it isn't for lack of trying to find the answer. I even searched the internet for an hour or so, and found only that no one else seems to know either, although quite a few people are out there asking. I did discover that there are quite a few bars scattered around the country that call themselves "Cooter Brown's."
According to my reference sources, "Drunk as Cooter Brown" or "Drunker than Cooter Brown" is a well-known saying in the South, and is first attested in print in 1967, though it's probably much older. The "drunk as" comparison, of course, is itself a staple of popular speech, and has been ever since one of the first known examples, Chaucer's "drunk as a mouse" of 1386. My personal favorite in this genre would be a toss-up between "drunk as a bat" and "drunk as a boiled owl," although "drunk as a wheelbarrow" (1709) has a nice surrealistic ring to it.
As to "Cooter Brown," it may well be that there once was a man of that name who became legendary as a drunk. If so, the exact circumstances of his accomplishment seem to have been lost to the ages. I suspect, however, that "Drunker than Cooter Brown" may have sprung from another Southern phrase, "Drunk as a cooter," which dates back to at least 1827. A "cooter" in Southern slang is, oddly enough, a turtle or tortoise. And if anyone can enlighten me as to how a turtle became a symbol of alcoholic inebriation, I'll buy a round of drinks for us all.
I have found several other posts like this too.
Randy