Part of the reason Star staggered the lugs on some of these drums was: 1) so they could use a shallower shell, allowing for choice of lugs, and b), see number one. On the bass drums, it was only for continuity. It was a pain to use a bass anchor, but a good old leather strap attached to a brothas throne would take care of that! It had nothing to do with spreading out the load, as far as I can tell, because I have had MANY Star shells pass through my hands and have seen no evidence other than using a shallower shell. Usually you will see this in the latter era of 6 and 9 ply, no re-ring shells...
Oh, and the plastic heads were, at the very first, an Evans stencil....and until about 63, they were "calf unless specified..."