Searching for im6657mi Window Roller

I'm looking for a roller for a Milgard Styleline window. Its called a Universal roller assembly. Part #IM6657MI
What you can't see is there's 2 holes in the bottom of the frame holding the sliding glass window the roller attaches to. the bottom of the roller has 2 small tips that fit in the holes. the holes are only about an inch apart from each other. See attached pix