There is a picture of the 'Original Ethiopian Serenaders, aka Boston Minstrels', presumably the same one mentioned above on Wikipedia, in Nathan's Dna Emmett and the Rise of Early Negro Minstrelsy. it is from the cover of a song sheet of the troupe (New York, C.G. Christmas, 1843) It states 'as sung by the six original Ethiopian Serenaders' and in 2 separate illustrations there are 6 performers. The top picture they are wearing tail coats. Second grotesque charaterisation in striped tops and jodhpurs.

Line-up in first pic is triangle, banjo, flute, flutina, tambo & bones.
second pic, tongs, banjo, drum, flutina, tambo & bones.