I'm not sure that will be possible if the page was updated to the new information in Firefox's cache.

Firefox has an index of the cache available from the about:cache page, but it doesn't provide a convenient way to view the cache contents themselves. Maybe there is a third party program to read out that data? (I'm aware of one for Windows, but I don't know about Mac.)

Thanks for trying, but that's not a solution I can use. You seem to be unsure of the cache contents if the site was subsequently visited (which it was in this case). Also, I have a Mac... I did find a "tool", but it was for Windoze only. Are there no extensions in Firefox that support this?

For the future: Is there any way to cache (or otherwise retain) an inviolate copy of visited sites?? - by inviolate, I mean a copy that's not over-written.

Thanks, ~S

It's true I don't know what is in your cache. To see when a page was last updated in the cache, you would need to check the list through about:cache.

For the future, you can manually save pages (using File > Save Page As or printing to PDF), but there's no built-in way to set Firefox to do it automatically.