Hi Christopher ,
Have you checked the Hopewell Colliery they do mine experiences
http://www.hopewellcolliery.com/
Excellent little restaurant as well, lovely food...

I am from the Brown family and researching them, My Granddad Benjamin Martin & his brother Amos William Brown were miners & owners of mines in the FOD.
My Father Gilbert Benjamin was also a free miner, following in the family tradition !
Kind regards, Roger