oldgmc: To bad you didn't post the pictur first, it would have saved a lot of wear and tear on my keyboard.
It still appears to be a Monarch but I'm intrigued by it not having any internal valving so it must have gone to a sperate directional valve. Does this thing have twin cylinders? Reason I ask it that the return line with the ball valve has a tee in it. I assume this allows for the return from two cylinders. Frankly I'd say it is basically unserviceable with this setup and even dangerous. Ball valves aren't made to hold the kind of pressure even an old pump could produce. Maybe you ought to think about replacing it with a newer unit if you intend to use it.
