I don't think a specific archive search button has been set up yet, but you might try the google search under the search pulldown on the menu bar up near the top. The archives are still there (I have a couple of IE favorites that point there that still work).
I just tried the archive search link and I was given a forbidden access error. I've been looking for a part number for a couple weeks now and I finally found it in the dieselstop archives through a google search. If I could have searched the archives when I started, I'd be two weeks ahead. Please update the search function so we can use it again, thanks.