It looks like the old site has been extensively vandalized. There are many redirects to a webserver in China from a user Atocori. The website is dead, but it was probably a spam/hack site.
I've reverted all of the edits in the 5200 section by hand, but there's a lot more vandalism in there. It would be great if the admin would revert the changes then lock it so it can't be modified again until it's migrated.
Or, migrate everything, then shut it down completely.
There is quite a bit of missing information on the new wiki - the N5200 FAQs and such don't appear to have been moved across yet.