@ ARDRUMMER,perhaps my original post was to wordy/disorganized,but only difference between the S/L and rockers is the bass drum thickness,Rockers all 4 ply about 1/4 inch thick, S/L toms 4 ply bass drum 6 ply at around 3/8 thick.Check this linkhttp://www.vintagedrumguide.com/ludwig_rockers.html
I have an original copy of the 1984/75th anniversary Ludwig catalog that is a slightly different version of the one posted in the main VDG site. It doesn't show the "S/L" series at all. In the version I have, what is shown as S/L series here are now labeled the Rocker series. Same classic series lugs and thinner shells than the classic series drums. Same pictures as the S/L series, just renamed Rockers. Then there is the one set of Rocker II's shown. Those have the old "Standard" series lugs with the granitone interiors to the shells.
So, depending on which version of the catalog you have, they could be S/L series, or they could be Rocker series. Either way they are still great drums.