The above reference for LHR transponder settings can be found at:
UK AIP LONDON HEATHROW (27 Oct 05) AD 2-EGLL-1-11
It's available at this address:
http://www.ais.org.uk/aes/pubs/aip/p...es/302LL01.PDF
Access to this website is free - you will need password access, which I recall was simple to fix.