The "worth it" thing is dependent on a lot of things.

Is it worth it to you- regardless of what the value of a pristine bike is- is that bike special enough to you to dump money into it? It seems something like a Schwinn Varsity in prime mint condition is worth like $80- are you willing to dump $200 into it to make it look like something you're proud of riding?

Is it for you, or to resell?

What does "restore" mean to you? Are you talking 'period correct' or 'catalog correct' restore? Or are you talking 'updating,' 'upgrading,' or 'modernizing?'

I have a 1986 Trek 400 Elance, the 2nd from bottom of the line Trek- but I think it's beautiful and rides wonderfully. I've spent a fortune dropping Top Of The Line parts from around 1992 onto that bike. IMO- it's a cool, beautiful, inspirational bike. To anyone else- it's a fool's errand.

I would seriously refrain from going full-on, "restoration" mode until you know something about bikes and what they mean to you. Otherwise- fresh grease, new cables and housing, replace broken/worn parts... that's great for a great riding bike that's cool on so many different levels.