The cache is NOT at the posted co ordinates; these are for the parking at Blackaton cross.
Stage 1: Use your OL28 1:25000 map
At the Lee Moor triangulation point, you can see the spoil heap at Red Lake in the distance (it's a clear and sunny day for a change). You head directly toward it until you meet a river; approximately 80m to your left is a small brook. You follow the brook, gaining height until you reach the highest point. From here, you follow a bearing of 330deg for 2.2km. You can see a granite cross to your north so you head to it. Which OS grid square are you now in? Grid = ABCD
Stage 2: Visit the trig point and obtain the four digit number from the base plate. Trig No = EFGH
The cache can be found at:
N 50 (A/E) (A-H+B) . (C+B) G (E+F)
W 003 (F+H) (A+B) . A (C-G) H