The superb Victoria British History website's always worth searching for text and occasional maps wrt history of the area, altho it sadly doesn't cover all of the Forest area. It's essentially a compilation of many snippets and references from all available archives & sources. Among other things it states
"The works at Ayleford may have been replaced by the Lower Soudley iron-works, ½ mile further up the Soudley brook and, like Ayleford, on the Hayhill estate. The iron-works owned by Edward Jones that were rated in 1824 may have been at Soudley rather than at Ayleford, for a map of the same year marked a pond, mill, and foundry at Soudley. The works, which lay beside the mineral railway-line from Bullo Pill to the Forest of Dean, were occupied in 1839 by the Soudley Iron Co., and were called the Great Western Iron Works in 1879. By 1885 they had evidently gone out of use, and by 1901 the course of the railway-line had been diverted to cross the site. The pond made in the brook above the works had gone by 1920."

From: 'Newnham: Economic history', A History of the County of Gloucester: Volume 10: Westbury and Whitstone Hundreds (1972), pp. 40-44.

URL: http://www.british-history.ac.uk/report.aspx?compid=15751&strquery=soudley
Date accessed: 22 September 2012.

For many other references to the various ironworks in Dean thro the ages, including at Soudley, see
http://87.248.112.8/search/srpcache?ei=UTF-8&p=great+western+ironworks+soudley&...

Re photos I've looked in "The Old Industries of Dean" by David Bick but sadly Soudley barely gets a mention, this book altho excellent (and only a few pounds secondhand on the usual auction sites etc) is largely based on the mining industry.

Re prices of books on another wellknown internet sales site, Hart's book is currently available from £35 to £216 !!...... this site often has price oddities, sometimes incredible, as sellers use automated pricing systems that are adjusted, often incorrectly, if special/signed etc editions sell at auction etc etc. This applies to all forms of "collectibles", I think many sellers are happy awaiting those rare millionaire money-no-object collectors. Meantime I suggest regularly scouring the auction sites as bargains are there to be found, especially if the seller hasnt arranged their auction to end on the popular hence competitive Sunday evenings.
Good luck !

Good, glad to be of help.