The April 2010 issue of British Railways Illustrated magazine has an article with lots of photographs of the Khyber Pass line taken by Gavin Morrison in the 1970s. There is a companion article about Pakistani narrow gauge in the April 2010 Railway Bylines, with basically the same text but different pictures.
The text isn’t especially detailed, being a brief description of the visit, rather than a history of the lines, but there are some very nice pictures of steam engines in action in spectacular scenery.
Sadly the Khyber Pass line is now out of action, with sections having been washed away and revival seemingly a distant prospect – unless the Chinese decide to rebuild and extend it to serve their Afghan copper mining concession at Aynak.
The 2’6″ gauge railway from Bostan to Zhob (Fort Sandeman) has closed. The track was lifted by the authorities to prevent (further) theft, although the government has announced plans to rebuild it as a 1676 mm gauge line and construct a 150 km extension to Dera Ismail Khan, cutting 400 km from the distance by rail between Quetta and Peshawar.