There used to be a writeup about the Head LP and Nik on RedTelephone66.com, a psychedelic music site about obscure and out of print albums from the 1960's and 70's. But that site has recently disappeared. Here is a capture of the info from that page:
Fortunately the information about the Head LP on the Hippy.com site -- "dedicated to the hippy in all of us", ha! -- is still up:
And finally here is the music used for the Beaker Street bed, from the 17:00 minute cut "Cannabis Sativa".