So......Slingerland put the wrap on first, before forming the shell, too?

I am just curious, but I see a lot of very knowledgable folks here posting about the thickness of vintage shells when wrapped vs stained finishes. An example would be a "P" or "M" stamp inside a Slingerland shell. It makes complete sense to me to think that a shell destined for stain or paint would be thicker than one intended for wrapping. In fact, I have a Slingerland student model snare from the early 60's that suffered under the output of an aerosol spray can from a previous owner, badge and all that I re-wrapped and then found I had very tight fitting heads. I later learned what that "M" stood for. That instance seems to substantiate the claim. My question is this: while that makes sense to me and does appear to be the case, how was that actually accomplished in manufacturing. I can't possibly imagine that any manufacturer had a second set of molds to produce a slightly larger painted or stained shell. That would make the notion of a cheaper painted shell completely incorrect. I have never heard of a 4 ply with re-rings Slingerland or Ludwig shell so I suppose it was not the case of adding a "finish ply" to the exterior of a three ply shell. Was it that one of the three plys (presumably the outer ply) happened to be thicker for a stain/paint layup? Again this seems labor intensive which doesn't make sense to me. I would have assumed that, to keep costs down, the only difference between the two types of shells would be the finish quality of the outer ply. Make sure the shop guys use the good stuff for painting and staining and use whatever is sitting around the shop floor for the wrapped finishes. What is the story behind this?...just proving that I am NOT a guru.

No they did not.

That's a fact. The Slingerland interior shell stamps were for the workers down the production line to indicate wether the shell was to be wrapped or a natural maple or stain finish was to be applied. M=Maple and P = Pearl.. as in Pearl wrap...The question about different sizes is a good one though. Recently I asked Precision drum co. to order a custom made shell from Keller that was 3/16" smaller than standard size. I was told this was not a problem because the mold machines were adjustable from the starting point of the 1st layers of maple. So my custom 10" replica Camco tom came out to be 9 13/16" in diameter exactly and just what I had asked for while maintaining the thickness requested at the same time. Hope this helps.

Adjustable molds...interesting. In reality, I wonder why the manufacturers cared about adjusting the exterior size of the shells in the first place? Perhaps they felt if they were producing a 12" drum that they assumed end users would be less than happy that their painted or stained 12" was actually a tiny bit undersized. As we know now, having an undersized shell would be a good thing. Then people would really have talked about stained drums sounding better than wrapped!