Re: 1967 Inside door handle orientation
FWIW, the 1967 El Camino Brochure shows them horizontal several times as well. But I would guess it is also a matter of preference, it isn't like you are modifying anything that isn't reversible correct? Mine are like the top picture, but I know that the door panels have been off at least once about 15 years ago.
1967 El Camino Malibu - Deepwater Blue
ZZ4 350, FiTech 600 complete!,Roadmaster tank, 700R4, Underdash A/C in progress, JGC Steering, 1990s truck serpentine.