I thought the point of this discussion was that this LP seems to be a very early quad recording, so it's most likely EV-4 or Dyna. I believe QS predated SQ as well. QS recordings often were released without mention of the encoding system. That might be true of Dyna as well, although you would think that all EV-4 would be labeled as Stereo-4, but for very early releases who knows? I don't know of any SQ LP's released without mention of SQ, and usually they carry a logo as well. SQ was a latter quad development, that's why we are overlooking it here!. IMHO SQ had less shortcomings than QS, in the beginning (pre-Vario-matrix) at least! And in the end with Tate!
Well put Ken .