First order of business would be to know if there is only one chainring or are both there?
Williams cottered cranks were original, needing to find rings and possibly chainring bolts would push me to possibly replace the cranks.
The Pedals if original should rebuild well.
Original gearing was Huret, note the brazed on cable stops adjacent to the downtube, hopefully still there.
I would stay Huret.
The rims if intact were Dunlop lightweight steel rims, 32 front and 40 rear, if those are still there, I would stay with them.

Great bike in its day. Pretty lightweight considering all the steel parts, my parents were under 24 lbs each.