Anytime I find a gem I think is a keeper I do a total dis assembly, overhaul all bearings, replace any rubber/soft components that seem at all questionable, true the wheels and give everything a really good cleaning in the process. The end result is a bike that is "nicer" than new with everything lovingly adjusted and lubed much better than it probably was when it was first purchased.
The end result is a bike that is as good as it will ever be.
If it is not a keeper or not special to you just a re-pack of the hubs, headset, bottom bracket, along with new tires and maybe brake shoes should get it in service.