Browsing the list without actually counting, I've seen a lot of those. There are also some on the list that I recognize but am not sure if I've seen them or not, probably have though. I've also probably seen a lot more than I'd be able to count simply because I don't know the names of most of the old movies on the list.

Duck Soup being on there makes me very happy though.

I stopped counting at around 260 or so. I'd counted 55 movies. I've probably seen the majority of the more recent listed ones.