Queen in Mono

only information is about length 3:30 minutes

Yeah it's 3.30ish. I meant poor labelling on the tape they must've used when compiling the release.

Does the single edit exist in stereo? Maybe that's the issue? I like they they used single edits on GH - tidies up the catalogue.

Yes, stereo version from 1973 & 1975 Elektra common singles 7" USA and Japan... wrong labeled 3:42 instead it is 3.30

1975 version is labeled 3:29 but is the same elektra single edit

Poor labelling then :)

Or maybe they put the mono version of KYA on GH on purpose to save some space on the LP? Songs in mono take less space on vinyl than in stereo, I think?

Maybe, although the whole collection was running about 10 minutes shorter than the UK version.

maybe for press quality? maybe not... no i don't think so... poor quality control, a simple mistake, noboby care... as it often happens