I need the same part. The dimensions in the photo are stamped on the metal part of the front roller, just above the three holes. The wheel diameter is 3/4 (rounded wheel, not square edge. nylon), offset of the front roller is 3/16. I nearly gave up finding even a photo of these and have forgotten the rear hanger offset.
I am curious how they made out. I too have the exact same brackets and sure enough I am looking for these brackets for two different closets. Ran into the same issue the big hardware stores don't sell anything that matches. Looking to see which brackets they used to fix their doors