Hi,
I will post information as I find it, as I don't know how much time I will have to help. The first thing I found is a 1963 article (emphasis is mine) that noted that: "Geno of California is named for Gene Ostrow, a 29-year-old visionary, whose flair and imagination have brought instant success to the year-old firm. He thinks the type of sportswear upon which the reputation of the California fashion market was first established has been absent from the scene for some years, and he is determined to bring it back."
Also, please note that the other name is spelled "Erni" (without a final 'e'), in case you are searching for that name.