I believe the shells were described as "Select American veneers" in the Cat,most people think it was a maple and poplar shell,I have a 1983 S/L kit the line that that preceded the Rockers,same shells except the kick is 6 ply.I would believe there is maple in them,I have had the kit down to just the shells and wrap and they are pretty heavy,heavier than what I imagine all poplar would be.
I have seen a quite a few instances where people removed the wrap from S/L and earlier rocker kits and found a nice looking outside ply on all the shells nice enough to do a clear coat and have a nice looking Natural maple finish kit.
I originally bought my S/L kit because I wanted the Classic Lugs and hardware to use on a custom build,but the kit sounded good,so later I went and slowly found the used mini classic lugs etc and put then back together as a beater/gigger rehearsal kit.The earlier rocker kits had mini classic lug casings on toms,later had the rocker / standard lugs,if replacing the classic lugs with new ones would be pretty darn expensive,I found the 50 lugs I needed for between 1.00 1.50 a piece,most were in fair to good cosmetic condition.I would bet those lugs new would be close to 15 bucks a piece these days.The Rocker type lugs if you can use them would probably be cheaper.I know that the standard type lugs and the classic lugs,don't know if it is the large classic or mini classic is interchangeable with the standard lugs I believe.