Slingerland.
The "Fiberglass shells" were Pearls Top of the line at the time, very punchy and very loud.
Personally I prefer the Wood/Fiberglass, still pretty loud, but with a bit more tone from the wood. Non of these drums are really expensive, but in my opinion the best bang for the buck that you can find.
Billnvick.
I had no idea that there were a thicker version of the FG Shell. -Keep learning every day ;)
My thin shells however were actually fitted with Hex shaped mounts that they used from early 70's. (Not the thin hex mount from the 60's).
Did the thicker shells have the same colour on the inside? -I have heard of (but never seen) fiberglass shells with a darker/Tan colour on the inside.
Regards/
Johan M