If it was in a radio station archive, it'd be the promo they were sent.
I seem to remember when all the BBC stock turned up 15 years or so back, there was talk that the BBC had many titles in triplicate and, as previously mentioned, had libraries scattered around the UK which were being assimilated. So they were downsizing to "just" having everything in duplicate.
I know somebody who visited the BBC library for a Record Store Day feature a year or two ago and apparently it was absolutely vast - just an insane amount of records. https://www.bbc.co.uk/programmes/b08mdly5
And lastly, apparently, there was a feature on a daytime show in the 80s where listeners got in contact with a story about a record they had which had gone missing - the circumstances surrounding it etc. I think they finished it when listeners would get in touch claiming to have lost their Tintern Abbey single (£1000 psych single, for example) while at a wild party, but eventually the powers that be clicked that a few of the stories might have been made up for nefarious purposes!