Thanks everyone, but I'm afraid nothing will work to weed out anything not 1959-1971 Nikon F only. Any other keywords would also go to filter out a portion the F's themselves. Especially words like "manual focus" or "body" and the like. Remember, people who know nothing of cameras and simply put up thrift-shop items, don't use these words.Come to think of it, without a finder, the Nikon F has no model stamped on it at all.
That's not always bad, poorly listed items get fewer real buyers; yes they are tougher to find but can be better deals. I've done that several times.
Also I always look for bodies with lenses; many times the lens can be sold to cover a good share of the total cost.
Mark Barendt, Beaverton, OR
"We do not see things the way they are. We see things the way we are." Ana´s Nin