Here's a nice animation of the workings of the 1911 trigger group. To my admittedly inexpert eye it looks like the guy has done a great job.
He says he's going to continue making animations showing the various mechanical workings of old slab-sides. I hope he follows through.
Inside the 1911: The Trigger Group - Album on Imgur
There are three frames, so don't forget to click through all of them.