PC was a great brand. They really understood quality control and even designed their own production and QC machinery to keep them ahead of the game. They weren't cheap, but everyone in automotive repair knew that purchasing this brand was the way to go.
I remember buying PC piston rings back in the 1970's and 80's, but they were already part of Dana Corp. by then. Now they're part of the German Mahle Empire, and I don't know how they stack up as far as quality is concerned these days.
No clue when the brand disappeared, but i do recall dad always choosing the brand when it was an option when I was a kid.