This is the final puzzle cache for a series. The other caches are straightforward traditional caches: GC7WQRV, GC7VAQM (now archived but available to view), GC7T9J2, GC7TFFQ, GC7TWHW.
These caches ask the finder to look about them. Within a specified radius from each cache is a hint or clue (there is no hint/clue in the actual caches). The hint/clue is something physical, ordinarily occurring in this location (i.e. not placed there by the cache owner) and in plain sight. Using your powers of observation, and the hints provided by the names of the caches, you will need to deduce the title of a book in a well-known series of much-loved stories for children based around a central character and his friends.
Once you have the title worked out you need to list the names of the central character's five main chums. Then count the letters in each name. Each name will give you a two-digit number. Find the digital root of each number i.e. just add the digits in each number together and they will give you a single digit number e.g William Watson = 13 letters so 1+3=4.
Now, list the five chums in alphabetical order by their FIRST names. This will give an order to your five numbers. Simply assign the first number the letter A and the fifth number the letter E. Then answer the equations to find the final co-ords.
S45 5S.TUV E170 3W.XYZ
S= D
T= D - 2
U= B - 5
V= A - 4
W= D + 1
X= C - 3
Y= E - 5
Z= E + 1
The final can be approached from two directions, neither of which will be particularly straightforward. One will be physically easy but very exposed to traffic and muggles. The other involves a slippery bank but possibly affords more cover (terrain rating is for this option). Your choice. At GZ have a look around and see how there is something nearby that fits with the theme of the cache (hint: iconic images recently repainted).
200ml snaplock. BYOP.