I have attached two links for a source of breakout boards for your IBM 2880 PSU.  Both J4bberwok and Finksy are trusted members that support this forum.

 J4bberwock
      https://bitcointalk.org/index.php?topic=738527.0


Finksy
https://bitcointalk.org/index.php?topic=966135.0

Good Luck on your project.

  /s TuffToad