Solved my on question. It appears as though the Penberthy is a similar construction knot as the Klemheist. The difference is that instead of using a loop and and forming a bite on both ends, like the Klemheist or Prussic, the Penberthy is tied by forming two loops on both ends and wrapping in a similar manner as the Klemheist. Somebody correct me if I am wrong.
I believe you are correct. IIRC the Penberthy is a single strand with end loops vs the full loop on the Klemheist. They both work on the same principle.