I think someone mentioned it is string through body only - not true. This bass can be strung either way - Ibanez went to a bit of work to make the holes in the bridge plate keyhole shaped and routed underneath so you can stick your string ball in there and NOT string through the body unless you want. Which is something I've often toyed with on other basses - loading my 2-3 lower strings through-body and upper strings through-bridge.
I think of the "oversized" bridgeplate as a humbucking shield for the larger bridge pickup. And massive sustain and connection to the body.
The "oversized headstock" - seems more of a visual trick of the light maple against the very dark headstock. Just measured - in reality it is not quite 1/16" wider at the widest point than a newer Epi Thunderbird 5. THe Epi looks skinny due to 2-tone finish on head.