Divorce records are handled by the Department of Court Records Civil/Family Division. While no on-line indexes or records are available, records may be obtained on site or by correspondence. Older records may be in storage and have to be ordered.
I've read the transcript. My mom had a copy. It's not what most say, but interesting. Order it from Allegheny County Records as noted above. I do not know what mom paid, but I'm guessing many dollars because of the huge number of pages. You do not want the simple findings record but the transcript. It comes in two parts. The first trial is represented in a paperback book called the Defendant's Paper Book. The second part, much longer, is the appeal record and it is typescript double spaced. About five scattered pages are missing from the original record. But context suggests that nothing earth shaking was on them.