I spent the past 4 days in Cambridge, for professional reasons. I looked in advance for shops in the city and came across MNG-AJM Games and Collectibles, Andy Merritt's business. He has a mind-boggling variety of games in stock, mostly used and little known, but also several in shrink, besides some books and magazines. Andy produces a monthly catalog of a small subset of his stock (see e.g. this month's list) but the easiest is to e-mail him a list of the games you're looking for. That's what I did and he had La Strada and King Me! in excellent condition and at very reasonable prices. He even delivered them in person at the college I was staying in. I'll certainly keep Andy in mind for future acquisitions of out-of-print games.