In the initial post regarding the Durotriges, it states "they did not use coins or have any large settlements." This is not correct. The Durotrgies had their won coinage, examples of which can be found here:
http://www.gilliscoins.com/coinage/celtic/durotriges.htm

This site also illustrates the coverage of the coins:
http://www.roman-britain.org/tribes/durotriges.htm

As an FYI Durotrgies means 'water dwellers.'