slingerland duco drums outer ply is always maple from the late 30's until the 80's

ha well that definitely explains that. The Vintage guide didn't mention that, just mentioned M-P-M shells until 63 so i was super confused. thanks for clearing that up for me.

Most (all) painted drums have a maple outer ply because maple is a smoother wood that lends itself to the lacquer finish (Duco was a brand of fast drying industrial lacquer made by DuPont that most of the drum makers used). Conversely they used mahogany on wrapped drums because the more open grained wood of mahogany worked better with the glue they used to attach the wrap.

BTW: If you're planning to wrap that shell be sure to test it first to be sure heads will still fit afterwords. Usually if you try to add a layer of wrap to a vintage shell that was painted the wrap will make the shell oversized and heads won't fit. This applies to Ludwigs and some Slingerlands from the 50's and 60's and before.