Brad -

IIRC, early ships with 16.5/16.6 extensions had no additional control
surfaces.

Ships with 17+ tips tended to have an aileron extension of some kind.
As far as I know, only later-model ships have tended to have the
polyhedral, and from what I understand its more about preventing
wingtip scrapes (easier to leave the wingtip skid on the non-removable
part of the wing) or requiring a beefy spar in the tip exension (to
handle ground loads) than anything else.

Enjoy,

--Noel