I've just uploaded a set of photos from Speedwell Mine in Castleton, taken in Pit Top Passage above the Bottomless Pit, on a rare, with-permission trip to examine the limited workings up there. Brass waistcoat buttons were found and retrieved for conservation. I've been working a lot in Speedwell over the last year or two on various re-documentation trips, especially in the Pit Props Passage series, and will continue to post examples of what's been seen so far as and when I can.
http://www.aditnow.co.uk/album/Speedwell-Lead-Mine-User-Album/