Nope, Originally Burke later bought by Powermatic (both under Houdaille Industries, I'm not sure if Powermatic bought Burke or Houdaille bought both). Houdaille also had Burgmaster under their umbrella.
I don't think they ever had a Rockwell connection.
I'm not suggesting that you change anything (it might just add more confusion) but I believe the late 1960s - early 1970's Powermatic metal lathes were more or less identical the the Logan versions except for paint and decorations.
I just did a search and we don't have any files in DOWNLOADS with the word "Powermatic" in the title. If any ever do turn up and you turn out to be right, I'll add "Powermatic Lathes" to the Logan/Wards Category title.