According to this interview Garry Marsh received some sort of "cease and desist" demand from Ringo Starr's lawyers.
Sold a total of 500 copies.
An advertisement in Adventure Probe Volume 7 Issue 2, for the Number 9 re-release in 1993, mentions "now available" 'pre-publication copies' of 'Beatle Quest 1.5: The Magical Mystery Tour' for the Spectrum.
The original C64 was adapted in 2021 to make an unofficial version for Plus 4; see here.
[+] Users currently playing this game
The release Spectrum version can't be completed due to it being hastily converted between Quill versions in order to add pictures. Fortunately there is a bugfixed version available. Shame that the game is not worth the trouble. Strictly for Fab Four fans who will get all the references.