Yeah you are right, according to Wolfgang Steinicke, which was written April 2008.
"
It is sad to tell, that all my data are no longer presented at the NGC/IC Project website. This is due to a conflict with webmaster Bob Erdman, who has terminated his activities for the project last year. His "Historically Corrected NGC", first presented on the project website in April 2006, is a mere copy of my "Historic NGC" which is evident by an overwhelming amount of facts. The necessary acknowledgment is still missing."
See
http://www.klima-luft.de/steinicke/n...000/Explan.htm
Basically it looks like the backbone of the site was just withdrawn. (and rumour says there maybe some alleged difficult legal issues as well.)
Pity it was a great resource on the Web, which seemingly took some significant effort to keep and maintain. It will be missed - but like everything - nothing lasts forever. RIP.
NOTE: I also believe this announcement and question was made in the somewhat quirky American Amastro group.