Hello Steve,
I was puzzled by your bicycle's shifter braze-on when I saw it on the Show Us Your French Bikes thread. Had not before seen one quite like this.
Am not able to see the presence or absence of bb cable guides as your photobucket account will not fully load on my machine. Likely a browser issue at my end.
Given the bicycle's birth time it is quite plausible that it came with a suicide front mech. You may well be on the right track there.
One thing to keep in mind is that french derailleur manufacturers made shift lever sets where one side uses a braze-on and the other is a clamp-on. In this arrangement the braze-on serves double duty as it acts as a no-slide pib for the shift lever clamp. Do not wish to assert that this is the case on your bicycle, just that it may be a possibility to keep in mind.
Have you been able to learn any additional information as to the history/origin of this manufacturer?