I've been working on a diagram of the timing system with specific locations and uses of every timing system component. I've put it up on DCC as https://dcc.ligo.org/LIGO-D1500201. I'd appreciate feedback regarding what else would be useful (while bearing in mind that I'd like this to stay clear and simple). I'm also happy to make extra pages if someone needs a detailed view of some particular element of the system that wouldn't fit into the overview shown.

Happy 4th!