Pleased I can provide a little history for you.
Re 1970 visit, I have little info and a distant memory!
We managed to arrange regular brake van trips with the railway society through good contacts in BR at both Derby and Leicester. This would often entail adding an extra brake van for us and also included cab rides. Different times eh! I can remember trips to Corby/Northampton, down the GC to Ruddington and from Coalville. Wirksworth was special with steam as well and although I was on the June 1970 trip there was also a previous trip before I joined Loughborough.
I've attached one last photo as it has a guy on the right who was obviously looking after us. (The middle 2 guys were on the trip yesterday.) Don't know if he was from Wirksworth quarry but someone may know him?