Yeah Matt, I think the subject is really interesting and need to do a lot more reading on it myself. The hammer lock was used by the Greeks (there are depictions of it), as well there are images of arm bars, kimura's and many other techniques that the modern grappler would instantly recognize.
Here is a link to a site that has quite a few ancient depictions: http://www.historical-pankration.com
And, I've uploaded the image from Beni Hasan, which shows grapplings techniques of the Egyptians in apprx. 2000 BCE