Just because a bike is about 40 years old doesn't mean it is collectable or worth anything at all................ Would you want to spend any time and money on a Mercury Comet, a Chevrolet Vega or some other type of drone type vehicle?
Indeed. And in this particular case, if it is a Turbo, it may be worth something as a complete bike especially if it is reasonably clean and in running order, or have parts on it that are worth something depending on condition (it's still not exactly a super valuable bike, but the Turbo does have a following of sorts), and if it is a standard model, it's just another old bike with nothing special about it. If it's a runner, it's worth more (in both cases). A non-runner probably isn't worth fixing ... in either case.
If it were me, and with my tools and my shop, I'd put at least a minor amount of effort into finding out if it was capable of running (since it is definitely worth more that way). Even if the bike as a whole is only good for parts ... an engine that can be heard running is worth more than one that's not.