You have more bike than you know. The "Hevi-Duty" mark
indicates that you have Schwinn INDUSTRIAL duty bike which
means Loooooooooooooooong lasting. These bike compete with
the likes of the "Worksman" industrial bikes out of New York.
So they have to be overbuilt by a wide margin.

So, you lucky devil, clean it up, take out any fender dents
and ride this workhorse. It might outlive you.