Looks like a 57cm frame to me.
I agree the brakes should both be Weinmann Vainqueurs, regards levers I've seen a fair few of these equipped with Weinmann levers with the safety extensions. The stem definitely looks like its been swapped out for a shorter later one. The post would look nicer is replaced with an alloy item. Hard to tell if it's just paint loss to fork as it should be half chrome half paint IIRC - do they have the little holes for safety washers? Mine did, so clearly they were replacements. I'd have thought the hubs would have been Maillard or possibly Pelissier originally.
If OP is interested I have a few few components from my old '77 Galaxy at the moment (TA Specialities chainset 48/36 with BB, complete Weinmann brakeset and lovely GB Randonneur bar & matching quill stem). They may not have been OE, but they would suit it nicely