Postal Tape Library name ?

[Milesago]

Many years ago my father was subscribed to a postal cassette tape library based somewhere in the UK. From about 1975 to 1981, approx. On joining, he received a catalogue from which he created a list of preferences. The library would then send him a leather pouch by post containing up to five tapes from that list. The cassettes themselves were housed in soft plastic wallets together with the j-card. They had to be returned within 3 weeks or so. We'd receive regular catalogue updates too. I remember one update explaining that the 'noises' heard through The Dark Side of the Moon were not caused by damaged tape but were actually intentional! Needless to say, I hijacked this resource once I became interested in pop music.

This was a privately owned, subscription based tape library, and not part of the UK library service.

Does this sound familiar to anyone and if so, what was the name of this library/company?