GD joined AH.com already in February 2008. Ever since, his time on AH.com has been spent alternating between being a lurker and a regular poster. He wasn't very active in his first year, but became increasingly active from 2009 to 2011, before going on a posting hiatus for a few years, and then returning as a regular poster in 2016.
Guernseydonkey's been active in the AH discussion forums, but most of his posts to date have been in various games in the Shared Worlds forum or in the forums of the Off Topic section.
If you're writing a timeline or story involving the Channel Islands, or just have questions about the islands and their history and cultures, chances are he might have an answer for you if you get in touch.