Worth restoring is your question, probably not. Worth restoring to me is saying will I get my money back that I spend and thats why I say no. A bike like that could need some carb work, tires, tune up, and be on its way to being rideable. Chances are the tank is rusted but you could pick something up used for cheap. You would be stripping a lot of the crap off of it that is probably rusty and more of your work is gonna be manual labor but chances are you wont get out what you spend even making it a budget basic cafe bike.