I've made a note in my files of a couple of things I was looking at a while ago in Gloucester RO which might help. One is FARR, Grahame - Chepstow Ships, which there are several refs to on Google. There might also be some info in Wye Valley Industrial History by Percy G Harris, which as far as I am aware was never published but is available as a typescript in Gloucester and Gwent ROs. As I am in Buckinghamshire I can't check for you, but perhaps some kind soul can, unless you are in the area yourself.

Joss