Potinara would be a combination of Brassavola, Cattleya, Laelia and Sophronitis, as those genera were formerly defined. I don't see any evidence here of Brassavola (or Rhyncholaelia) or Sophronitis influence. That doesn't mean they couldn't be there many generations back, but the only thing obvious here is Cattleya, both bifoliate and big monofoliate types, and maybe Laelia of the types now considered Cattleya. So C. or Lc. rather than Potinara, by appearance. Many many thousands of hybrids of that type of course, so I think a positive ID is unlikely.