Probably mid seventies judging by the simpler lugs. Early 70's and 60's models used more ornate nervex professional lugs.
Can you get a closer picture of the bar end shifters? I think you may be one of the lucky few that have a set of simplex retro-friction bar end shifters. They are rather difficult to find and retro friction shifters are probably the best friction shifters made.
For the stem, do you care about period correct parts? If so then look for older french stems on ebay, and avoid AVA stems.
Also closer pictures of the brake levers and calipers? They look like they might be universals, but I can't tell. That would determine where you go to find replacement hoods for the levers.
Also you can use aluminum foil and water to clean any rust off of chrome parts. A new chain is a good idea. You can also get modern top tube brake cable clips to replace those zip ties. Newbaums cloth bar tape is a good option if you want to stay with that on this bike. If I recall correctly those rims should be clinchers so a good option for gumwall tires are panaracer paselas. The brake pads may need replacing. I would also rebuild the bottom bracket, hubs, and headset with fresh grease.
Last edited by spock345; 07-07-16 at 10:33 PM.