Cambrian Trail - Bonus Cache Mystery Cache

This cache is only able to be found by completing the Cambrian Trail series of caches from Machynlleth to Newtown and collecting the letters on the back of each log book.

Parking is available very close by and the cache is big enough for some small swaps and trackables. Please replace the cache carefully. The location can be, at certain times, high in muggle activity. Please dont give the location away and come back at a quieter time if needed.
First, make a note of the letter on the back of each log book on the Cambrian Trail Series of caches.

Once you have all of the letters put them in alphabetical order.

Each letter has a number assigned to it below. Fill in the blanks of the coordinates with the corresponding numbers to the letters in alphabetical order. For example, if the first letter in your series is A, the first part of the coordinates will be N 51.
Good Luck!

N _ _  _ _._ _ _ W _ _ _._ _ _

A - 51
B - 5
C - 37
D - 52
E - 23
F - 07
G - 12
H - 38
I - 3
J - 42
K - 4
L - 67
M - 32
N - 2
O - 90
P - 01
Q - 31
R - 20
S - 77
T - 23
U - 58
V - 51
W - 73
X - 50
Y - 62
Z - 84