If you know the judge's name you can do a judges search on infodog then select past assignments under labradors. That will list all the judge's past assignments. Some of the assignments will have a hyperlink to the results. I donj't know why some have a link and some do not. Using this method I was able to view results from 1999.

A variation on a judge's search is to look up a specific kennel club using the AKC club search, then you can look at the past events tab. That will have results going back many years for that club.