Nellie Kirkham wrote an interesting article entitled "The Tumultous Course of Dovegang" which appeared in Derbyshire Archaeological Society and Natural History Society's Journal 1953, it includes a map shewing veins, shafts etc.
Another article she wrote which might also interest you is "The Draining of the Wirksworth Mines" which was published by Derbyshire Archaeological Society in 1963.
You should be able to view these articles at Matlock Local Studies Library as they hold all the DAS Journals. If not, ask Iclok as (from memory) I sent him a copy of these two articles sometime ago.