Recorded on 24 and 25 May 1965 at Kingsway Hall with the London Festival Orchestra (actually the New Philharmonia Orchestra) and released on Oct 1966 as Decca PFS4098 and Feb 1967 as London SPC21009.
Later reissued as CD 421 025.2.
This record weights only 122 gram and it's very flexible, so I guess it's a later (70's) pressing. But I'm not shure.
The M in the 33 triagle doesn't mean mono,see here.
M stands for Microgroove, so this record should be played with a (flip-over) cartridge in M position and not in N (normal groove, for 78 rpm records).
Stereo singles appeared directly from the start of the Stereo Era, in 1958 Here is one a year after.
Popular music was mostly played by young people on monaural record players, so there was no use to release them as stereophonic records.
Here you see the complete1969 catalogue of Philips HiFi products. The 22RH790 (page 3 of the record, the model above the pu- catridges) was the first receiver with a ( 3 - presetteble) electronic touch control knobs. If you repair this one notice the 300V supply for the neon indicator / memory touch control electronic devices. You might not expected such high voltages in a transistorized receiver! It gives you an unpleasant moment when you touched such a component, I noticed.