I grabbed some good screenshots though to bolster the hunt. The model in pink kinda looks like Mary Woronov, though obviously it's not her. But it's the one in red I've got a hunch on.
I had always thought she looked a little like Stockard Channing, but I knew that wasn't likely. But then, while doing other research, I found out about the actress Kathryn Loder, most likely remembered for playing antagonists in THE BIG DOLL HOUSE and FOXY BROWN, and, yes, with features similar to Stockard Channing


She does not have a very large body of work, sadly because she battled diabetes most of her adult life, and it claimed her in 1978. Now, why would someone who was getting speaking roles in films agree to an uncredited appearance on TV with no dialogue? Well, her only credit in 1975 is a fleeting appearance on "FAR OUT SPACE NUTS" with Bob Denver and Chuck McCann, which (at least on the copy I watched) she was not credited for either. So maybe she either lost her momentum and had to take lesser jobs, or was taking it easy for a while due to her health, and doing short bits that weren't too taxing. That seems plausible to me anyhow.