Full restoration with engine rebuild could very well make this bike worth that, but only if someone is willing to pay that. Especially if the mileage is correct. Worth is in the eye of the buyer. Try pricing out a bike with that mileage, pay a professional to restore via rechroming, repainting, repowdercoating, rebuilding, new parts, virtually unobtainable NOS parts, etc and see what it would cost you. Or what would a new modern bike cost you?!