All images now added. The glossy cover is showing its age, and don't look too closely, or you'll see where the stitching didn't quite match up correctly (it look long enough to do it once, I'm not doing it again!).
No mono or stereo markings anywhere on the sleeve or labels of this Aussie version, but A QUICK ONE sounds stereo to my ears (although fairly narrow), unlike the German version with the same catalogue number, and the UK version with a different number (why, if Polydor's catalogue numbers were supposed to be international, are there different numbers for UK and Germany & Australia?). Apparently the 2015 vinyl reissue of A QUICK ONE has the mono symbol on the labels, but so does that year's reissue of THE WHO SELL OUT, which is stereo!