He's in Louisianna...there you can have a pistol/shotgun/rifle lying in the front seat of your car, fully loaded, and as long as you ain't a criminal or DWB, it's perfectly legal...so brass knuckles ought to be no problem at all.
And if you are DEEP in the backwoods...depends entirely on your personal relationship with the local fuzz.
Brass knuckles are a silly toy, getcha one of These!!
Totally legal to carry in ANY state...as you never know when you need to work on an old motorcycle the Old Fashioned Way.
Hell's Angels STILL carry these...especially the convicted felons, as they're legal for anyone and do heinous amounts of damage. Do a search on the Hell's Angels sometime...them & the hammer go WAY back