In 2006, Culture Minister David Lammy announced that the Bests' ex-coal cellar was to be given Grade II listed building status and a blue plaque, after being recommended by English Heritage.

The house (built around 1860 by an unknown architect), had previously been owned by the West Derby Conservative Club, and was unlike many other family dwellings in Liverpool, as it was set back from the road, had 15 bedrooms and 1 acre (4,000 m2) of land.

[2][8] Mona charged half a crown annually for membership—to "keep out the rough elements"—and served soft drinks, snacks, cakes, and coffee from an espresso machine, which no other club had at that time.

[12][13][14] The Quarrymen played a series of seven Saturday night concerts in the Casbah for 15 shillings each, starting on 29 August to October 1959, featuring Lennon, McCartney, Harrison and Brown, but without a drummer, and only one microphone connected to the club's small PA system.

[15][16] The opening night concert was attended by about 300 local teenagers, but as the cellar had no air-conditioning, and people were dancing, the temperature rose until it became hard to breathe.

[18] Every Saturday thereafter, queues lengthened onto the street, which was financially good for Mona, as she charged one shilling admission on top of the annual membership fee.

[19] As there was no amplification, Lennon later persuaded Mona to hire a young amateur guitar player called Harry to play a short set before the Quarrymen, but this was only so they could use his 40-Watt amplifier.

[16][23][24] The reason for Brown's exit from the group was that he turned up on the seventh Saturday night of the Quarrymen residency at the Casbah with the flu, so Mona ordered him upstairs to the Best's living room to rest.

[17] It was in the Casbah Club that Lennon and McCartney persuaded Stuart Sutcliffe to buy a Höfner 500/5 model—known in Europe as a President bass—with the money he had won in the John Moores art exhibition.

[30] In 2006, Culture Minister David Lammy announced that the Bests' ex-coal cellar was to be given Grade II listed building status and a blue plaque, after being recommended by English Heritage.