The 2016 blacks beach shoot use to all be available on R.Prossers website (robertprosserphoto.cm) and that's where I got most of these in HQ (a lot are gone from there now) most of it is still available on his Behance site (/prosser) in HQ.
Over the years Robert and Janna have posted more outtakes on their insta's and his twitter (prosser_photo) which is where I got the rest. He seems to be showing he has more unreleased topless stuff on his insta at the moment (/Prosser_photography)