Thanks, that seems more accurate for a wagon.
Haven't found the '64 classifications yet.
In '65, it would have been classed B/S or B/SA.
In '66 & '67, C/S - C/SA
In '68, E/S - E/SA
In '69, F/S - F/SA
In '70, G/S - G/SA
This assumes the published shipping weight never changed, which I think is a reasonable assumption.