hcstang,
If you got the louvered hood the turn signals came with that option, you could not get the louvered hood and not have the turn signals.
As far as price, I can not find one in the pricing guides but that is because most guides go from the beginning of the year. In '68 louvered hoods where standard until the Dec 67 strike where they became an option to save money (just like dash pads, pillar pads, and quarter panel lights changes). I would look in the '67 options listing.
Doug