Most of the FM's back then would have originated from Mt. San Anotonio. I recall these stations being owned and operated by Victor Diaz. If there was an FM100, Victor may have made a deal for a better facility at 104.5, but now I'm speculating.
Victor, a member of the Diaz family from Guadalajara (which owned dozens of stations) did His and Hers in association with paul Schaefer of the automation company. They used Paul's equipment, and made a significant play in the developing days of FM in the market.