3) is right, the bike has had many component replacements.
The BB is a cartridge replacement. How does it spin? It may indeed be fine.
Looks like one Universal and one Mafac brake. Interesing, both "from the period". The pads are Kool Stop salmon replacements, which get high marks from most here, esp. in the rain. They can be noisy, but there are ways to adjust for that. Levers are Shimano 600 aero replacements.
RD is a modern-ish replacement. I always thought the dropouts on French frames had a different position for the B-screw rest, but that may not be the case with your bike. In any event, if the mech hangs in the right position and shifts properly, call it a day.
FD is probably a replacement, since it's shimmed, but is "period". At least it's not the (in)famous delrin Simplex pictured above. Should be perfectly serviceable. Eek, what happened to the front shifter? Are the parts still around?
Crank is the original Stronglight, one of the most beautiful bicycle components ever made. Something special about that star pattern.
Some would call the mix of components a "dog's breakfast", like something a flipper would throw together from found components. But knowing this bike's provenance, it's really just an indication that your father took care of this bike, and intended to keep it roadworthy.