Evening Graeme....found reference to both aircraft on a search for "Coupe Deutsch 1935".
Richard, I am not sure if either one of them is the answer, as I cant find drawings/photo's but the descriptions of both tick some of the boxes...particularly having the Regnier engine (which I'm sure it is). Also there is a reference to the Martinet having retractable undercarriage.
Logging off now as have a meeting to prepare for. Cheers