The cache is not at GZ. The coordinates will take you to a crossroads next to the Golf Course. At GZ you should be able to park & see a signpost.
How far to Exeter (Add 1st & 2nd numbers together) Ideford & Teignmouth = A
Exeter (Add 1st & 2nd numbers together) = B
Exeter (Add 1st & 2nd numbers together) & Ideford = C
Ideford & Teignmouth = D
Exeter distance in miles divide by 2 = E
Final coordinates
N50 33.ABB W003 32.CDE
Happy caching!