I claim no credit for the research on this, all the information about the Alan Freeman Matrix H broadcasts came from a chap known as Oxford Dickie (OD for short) in quadraphonic audio circles on the net. He's the one who has developed computer processes to decode Matrix H (and many other matrix quadraphonic formats).
Unfortunately we have no information on any audible differences when listening in stereo. OD had to attempt a decode of the existing shares of this to find that they weren't Matrix H. That's the complete 4 track share from Jon Stuart a few years ago (mini disc copy of the masters), then the two tracks from the 2011 remasters CD disc 2, and finally We Will Rock You from the KBFH compilation CD someone shared recently (I bought the CD online to see if it mentioned Matrix H or quad but it didn't).
I guess the obvious way to tell would be if Alan Freeman is heard as the DJ on the recording.