My Wife's all-original (except for replacement Rocket-Ray, tires & grips) 54 Panther, is 100% identical, except for the sleek Phantom fender-light. The only reasoning I can think of, is for price point. With a Phantom light, Schwinn would have been obligated to sell it at the higher (men's Phantom) price, and therefor limiting sales. Unlike girls, boys were "determined" to specifically have a Phantom, and they, or their parents, would pay the higher price. The manufacturing cost difference, couldn't have been more than a dollar, in those times. Yet the girl's Panther sold for at least $10 less, I believe. Never did we have a girl shopper, enter my Dad's Schwinn/Rudge store, looking for anything specific. Once they viewed the bikes, they'd usually choose a white and pink Debutante. In 1966 & 67, he sold an IDENTICAL (776) quantity of Schwinn's, each of those two years. In the 10 years that he was a dealer,
there was ONLY ONE WARRANTY CLAIM!!! That single warranty was the result of extremely abusive operation of the bike.