Could this refer to the List of Mines, published by HMSO?. I have handwritten notes including Derbyshire covering 1920-1938 & 1945-1949. These included owners, managers, employment but not output, & also (for Derbyshire only) a list of the owners of the various Liberties. These were formerly available on microfilm at Plymouth University but they seem to have got rid of their large collection of HMSO publications. The Inspectors of Mines & Secretary of Mines reports were also included, but have very little re Derbyshire - just total annual production & a few accident reports.