I've never seen an actual copy either. This one was posted on ebay recently - apparently lots of surface noise on it and a less than great cover. Still went with a £100 'buy it now' though. There can only be very few copies of this one out there, like you would love to hear it some day !
McNair is certainly an interesting figure in UK jazz. One track of his RCA LP ('The Hipster') was recently put out on the 'Impressed Vol 2' compilation. He was also a key member of Alexis Korner's session band CCS, renowned for their cover of that Led Zep track used by the BBC for all those years as theme to the weekly 'Top of the Pops'. Still ingrained in my subconscious !
Look out for his great work too (along with Ronnie Ross) on John Cameron's soundtrack to the movie 'Kes' and the Deram album released by Cameron, 'Off Centre'.