Just in case you aren't already spending too much time on the internet there is an extremely promising looking site for those who are fans of photographic ephemera. This is a site that will be posting a couple times a week featuring old gallery announcements and other paper goods that usually wind up in the dustbin.
His first posting is on various Ansel Adams Christmas cards which some were actual gelatin silver prints mounted onto personalized letterpress cards. More interesting to me is the Bernd and Hilla Becher announcement from 1973. He also includes interesting anecdotes about each piece that weaves a tighter web around this medium's history.
I know the guy who started it and I have to say that he saves gallery announcements even more obsessively than I have. He literally has thousands of them. That said we'll see if he has a copy of the Another Country exhibition card of Graham Smith and Chris Killip from 1985. How about the 'pig cakes' announcement poster from Martin Parr's Common Sense exhibitions. Check it out and I guess we'll see.