ART/MPC scope

Hello all, I just aquired what I believe to be an original Vietnam era Leatherwood ART/MPC scope. Other than the graduations, the only markings of ANY kind are the letters "ART / MPC" on the left side, and serial number 00XXXX on the left side of the elevation turret. It is graduated to 600 meters. However I know little about it. I've gleaned a rough understanding of it's adjustments and setting process from the website,(http://www.leatherwoodoptics.com) but was wondering if anyone has has any experience with this scope or something similar, as they don't list this model or it's manual. And it does differ in some ways from the newer Leatherwoods. Anything you can tell me would be greatly appreciated. Thank you.

Howdy Fireform. My buddy has a leatherwood his is a 3-9 that works on the cam assy (not sure of the model) for his you need to know the size of the target. It has ranging marks on the cross hairs and you adjust the power ring until your target fits and as you adjust, the scope raises or lowers on the cam assy to eliminate hold over it's a pretty neat scope. I'm not sure if this helps ya or not but it's all i no about them.
Joe