Weinmann 600 brakes and Simplex deraileurs! This bike is gonna be at least early 70's vintage, but more probably 60's vintage. Can you see a name on the cranks and hubs? That would also help. If its a French bike they will probably be Stronglight or T.A. cranks and Maillard or Mafac Hubs. You'll need to strip 'er down completly. Hubs, bottom bracket, everything! Inspect all bearing surfaces. If they are not pitted you can clean and rebuild. New balls for the bearing would be good too. If any bearings are pitted you will have to replace. Harris Cyclery is a good on-line place to get new replacement parts for vintage bikes. What they don't have they'll help you to get by pointing you in the right direction. Take your time with this project. If you do it right you will have a beautiful vintage bike. If you can determine the make there are re-finishers that can replicate the decals too. Enjoy the journey!