The above coordinates will take you to a location from which you can obtain the final three figures N and E of the coordinates of the final cache which are all that need to be changed. Please do not take or leave anything at this first stage.
The final cache is nearby, continuing the theme of the first stage. Please be careful when removing and replacing the “lid” – it unscrews and might be a little frail: please do not over-tighten. when you put it back
Why not continue down Peddars Way to find Not Mush Room and King Alfred’s Cakes?