The cache is not at the location listed! 
You can click the first image to see a higher-res version, and you can download a pdf of both images from here (5.6mb). You will need to print out page two of the pdf at A4 (on thin paper) before you set out. Make sure you turn off page-scaling when you print it out so it is exactly the right size).
Please put each part of the puzzle back exactly where found. If any of them get lost the cache will have to be archived as each piece is unique.
Another page from the diary (with extra clues -- though they're not essential) can be found in nearby Freston Woods.
UPDATE May 2021 Having discovered its loss, the final cache has been restored by samwiseUK who has left some amazing booty well worth finding.
Congratulations to jim4545 with the first to find (despite one of the coordinates being wrong — all corrected now).
You can check your answers for this puzzle on Geochecker.com.