I did a surface survey of Westcott mine with the late David Bick about 13 years ago or so.
From what was in the tips, this must have been quite a rich occurrence of copper mineralisation, albeit low-tonnage. Massive chalcocite (much richer in Cu than chalcopyrite) and chunks of solid malachite, both to 10cm or more, were recorded. Nothing exciting from a specimen point of view but they show the richness of the ore.
This style of supergene copper mineralisation occurs at a number of mines in the area: Huglith, Wilderly and Cothercott also have showings, but Westcott seemed especially rich.
Cheers - John