Do older grates have thicker metal?

Last night I was using a '70s-era 18" Bar-B-Kettle and it seems like both grates have thicker wires, especially the cookgrate. Is this generally the case for older kettles? Or do I maybe have a WSM upper grate in place of the original 18" grate?

Brad

yep, the older ones do have thicker wire. i noticed that when i replaced my grate last year.