I can't find the catalog to be certain this vender has the Avengers, but try
Shokus Video/the TV Connection
P.O. Box 3125
Chatsworth, CA 91313
Subject: Video Search: The Avengers (Rigg/MacNee)
From: email@example.com at BITNET/INTERNET
Date: 8/26/96 7:52 PM
For a while you could get the television series The Avengers on video.
They all seem to have disappeared. Video Source Book, 1997, says no
longer distributed. So, I thought I'd ask one more time, hoping
against hope that we might still be able to get a few episodes.
Thanks as always.