The 330 is my preference for gigging mainly due to the weight. 330s and Casinos have the spruce bit (rather than the more typical hollow body bracing) but no maple center. Here's the pickup cavity of my 355 showing the construction - the kerfed spruce parts make up the top and bottom then the maple block is simple rectangle in the middle. One way the Historics differ from the standards is the spruce part is quarter sawn Adirondack.
The center block on a 335 is spruce and maple - the models that used chromite were the ES135 and Chet Atkins Gretsch-alikes.
