Externally the 204 looked identical to the Boeing Model 6E, but a number of internal changes, including increasing the passenger capacity to four, gave it a new Type Certificate and model number.
Eksternal 204 tampak identik dengan Boeing Model 6E, tetapi sejumlah perubahan internal, termasuk meningkatkan kapasitas empat penumpang, memberikannya Sertifikat tipe baru dan nomor model.