Name this tool!

[derekf]

Going through trying to finish unpacking my garage, I came across a tool that a) I can't identify and b) I don't know where it came from.

Hopefully y'all can shed some light on it. From the appearance, I'd guess some sort of rivet gun, but I wasn't able to make it do anything with pop rivets, didn't try other types as I didn't have any to try.

It does not have an air inlet. It does not have any markings, serial or part numbers.

Here's the box it's in:

and the tool itself:

The business end of the tool:




On a completely unrelated note, I know that the three air regulators on the left (below) are the type that just bleeds off pressure when it's above a threshold.. is the one on the right the type that just regulates and prevents pressure above the setting from getting through, or does it do something else? I'm about to start piping my air, is this the type of regulator I should put right after the compressor to regulate all the outlets at the same pressure?