"Gina" in BG2 is at upper left on the cover, that was the early name for Mercedes, who went on to do many other movies, such as Hardball 14, Rocco's Initiations 4, and The Voyeur 20.
"Susan" is Suzanne/Gabriella Kerez, and she's the brunette at top center on the cover, with an awful haircut. Behind her is "Edina" who usually works as Edina, for example in Madness 1 (she does the sauna scene with Tamara NJoy).
"Sandra" is the reddish haired girl who shares Claudia's opening scene, I don't know her from anywhere else. "Dina" I believe simply is "Dina," she did a few other movies that I know of, such as for Patrick Handsome (one of the Precious Pinks for sure, #3 or 4). I agree with your other IDs, though Adrienne Klass took me a while to recognize when the movie was new, becayse she was apparently in the process of having some tattoos removed, and had lost weight since her Woodman days.
Now to HB13. I've only known "Chrystal" as Chrystal, she uses that name in many movies such as Exotic Illusions 2, A Bevy of Blondes, and Ass Quest 3.
"Miss Blondie" is Edina from BG2 above, and she shares the scene with "Tunder" who is indeed Sheila Scott in one of her first scenes after getting her hair cut short. "Agi" is the other girl in the scene, I think I noticed her somewhere else before, but nothing comes to mind.
"Inga" is simply Inga, she's a Russian girl who came to Budapest with her friends Mallory (in this movie) and Mary Blonde. She's the reddish haired girl in the dream scene which also has Chrystal, and has Liza in the blue wig as seen on the cover, and Inga also appears in Hardcore Innocence 2, Blowjob Impossible 1, and Killer Pussy 5 (along with her friends I mentioned).
You seem to know some of the other names in HB13, but for the record, "Eva" is the rather plain girl who shares Suzi Sweet/Agnes' scene, and who also did a scene for Hey Babe, Nice Tits at the same time. "Laura" is Laura/Orsolya who did some more Clark scenes and a couple of Rocco ones, she's in the background in Inga and Chrystal's dream scene. Mallory, Red Julia, and Liza are all known, and that accounts for every name on the front cover (I don't see an "Annie" or a "Bea."
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