I have not many ideas...you said that 184 is a close answer, and to look earlier: but I found no Peugeot model earlier than 1928-9, close to 184, and with matching measures. The only earlier Peugeot that kept a non aerodonamic look for some years longer, and big dimension, is the 601. I haven't found a better replay, so I try with 601 by Belvalette.