The excellent Wild Swan old railways book "The Forest of Dean Branch Volume 2", by Ian Pope of Lightmoor site fame, carries many old photos & history of the Hawkwell mine and various brickworks, it details how the Hawkwell Brickworks was rebuilt as the Coleford Brick & Tile Co in 1936, a 1960s photo shows it's perhaps 1/2 mile from the Northern United spoil tip.
It also contains a superb old photo of Hawkwell Row, a terrace of 16 houses built by Joseph Chivers for his mine workforce, as per Slowhand's excellent link the Row is still there at the base of Ruardean Hill overlooking the A4136 road near the Steam Mills/Cinderford junction, about a mile north-east of Brierley village.

http://www.zoopla.co.uk/property/1-hawkwell-row/drybrook/gl17-9de/9709844

see http://www.forest-of-dean.net/fodmembers/index.php?id=46758