Start with the correct book, the ANO
http://www.caa.co.uk/docs/33/CAP393.PDF
Article 86 which refers you to Schedule 10, also gives a proviso:
If the flight is intended to begin and end at the same aerodrome and does not include passage over the territory of any country other than the United Kingdom, the documents may be kept at that aerodrome instead of being carried in the aircraft.
Schedule 10 gives the following for Aerial Work flights:
Aircraft Radio Licence
Certificate of Airworthines
Flight Crew Licences
Certificate of Maintenance Review
Technical Log
Certificate of Registration
Interception Procedures
Article 16 Permissions if any.
The ones in blue are NOT required on a private flight.
The C of A is now issued by EASA under an EU Directive and must be carried on all flights (the original, not a copy), the exemption in Article 86 does not apply to EU legislation.