pageoneresults - 10:23 am on Jun 28, 2011 (gmt 0)

I'd keep them as 200s and change the content to reflect stock status.

I think BenFox had the most elegant solution. ;)

Don't over-engineer this one. You're better off retaining the historical value of those documents and just updating them to reflect the current status. It's also a chance to upsell the visitor on a comparable replacement as mentioned above.

It could be, in some situations, but Google has a very long and mostly bad history with dealing with 302 redirects especially around 2004-2008.

I wonder if we SHOULD be discussing 303 and 307.

The status codes 303 and 307 have been added for servers that wish to make unambiguously clear which kind of reaction is expected of the client.