Try asking at Diesel Equipment Company's Wiper dept.
1-877-307-7059 (Wiper Technologies).
Also, apparently Monaco had more than one supplier of wiper systems, so you might check AM Equipment's website also, here in Oregon:
http://www.amequipment.com/03_radial_wiper_arms.htmlI can't find a manufacturer or code stamp on my '06 Monterey wiper arms, though I haven't checked the mechanism "under the hood" yet.
I have a hunch AM Equipment is the manufacturer for our single piece windshield Montereys and other Beavers' wiper systems.
-Joel