Mark Kille
On behalf of a friend: "Okay, people who know stuff: if a friend of mine was looking to donate a large-ish collection of good-condition vintage SF, what libraries have the sorts of collections that might want such a thing?"
That depends entirely on where he lives. In southern Ontario, I'd say the Toronto Public Library. - DJF from Android
A Google search for "science fiction library collections" without the quotes will bring up a number of them, too. - LB needs a break.
Toronto Public Library and University of Calgary have the two largest collections in the world. Toronto's is bigger, while Calgary's is more along the lines of vintage periodical speculative fiction. - Soup in a TARDIS
If said friend is in the States, there's the Browne Popular Culture Library at Bowling Green State University in Ohio: - Katie
What about the EMP in Seattle? - Holly's favorite Anna
Thanks for the good suggestions, everybody! - Mark Kille