I just looked at the archive.php format and I dont see what you mean.
I’m trying to set up something like this:
[Previous thumb ] | [Next thumb]
[Prev title ] | [Next title]
[Prev excerpt ] | [Next excerpt]
While you’re currently on a post or a custom post type page. You would see this in the upper right corner or in a sidebar. The first two are very doable, not sure what to do about the last item.