PDQ. According to the notes for the Louie Bluie album, he acquired the nickname when a drunken woman at a party caught his surname and thought she was addressing ol' Satch hisself. When the woman realised her mistake she said something to the effect the "You're not Louis Armstrong at all. You're just plain old Louie Bluie."

Martin, Bogan and Armstrong made one or two superb records in the 1970s. I've no idea whether they're still available, but they sure are worth hunting down.