Slitherlink Rhomboid Mystery Cache

I've always found the Rhomboid tiling a tricky one. It's just so easy to miss the fifth line at one of the points where five lines meet. I used Rhomboid tiling in a D/T puzzle. The good news is that this one is a lot easier than the D/T one!

To work out the location of this cache, you need to do the following:

1. Solve the puzzle below (see the cache listing for Slitherlink Boot Camp for the rules about how to solve Slitherlink puzzles).
2. Locate the letters a through to u in the puzzle (i, l and o are omitted). For each letter, its numeric value is the number of lines around the cell.

The cache can be found at S 43 31.ABC E 172 34.DEF, where:

A = n + t + u
B = g + h + m
C = a + b + h
D = c - j - m
E = d + k + r
F = e + f + s

The checksum for A to F is 26.

The cache is a 200ml sistema in a hollow at the base of the tallest rock (might be a stretch for some to reach it). When placed it was well covered by a couple of stones and piece of wood. Please leave well covered.