Not sure its worth restoring. Could be fun to customise though
There are hundreds of different bikes made with the 'U' frame design, very few are of any major interest.
Did you try riding it? Does it ride well?
If you like the bike then its worth fixing it up. It could be fun to treat it as a blank canvas and try something different with it. You could for example add ape hanger bars and a low rider seat or use dropped handlebars and put deraileurs on it. There are however better old folders out there