Have you tried looking at the http://www.worldradiohistory.com website?
Go to the UK section on the first page and this narrows down the search a bit.
There is the Harmsworth Radio encyclopedia – a part work from 1923 in 20 parts and a modern Encyclopedia of Radio(2003) with 1700+ pages
Also complete sets of Babani paperback books, Practical Wireless, ETI Wireless World and similar and most of the computer magazines.
All free too!