You have lots of items that are close and may likely work ...so here we go.
I have included 5 pictures. The Outside diameter of the flat brass roller is 9/16".
The pin (.172") that holds the roller is worn along with the elongated hole in the roller. As a result, the rollers are recessed and the slides vinyl on vinyl. The overall outside dimensions of the Double Roller Assembly are used on a few replacements ... Good News! I think a Dual Ball Bearing unit would be great but I would settled for a replacement that allowed us to open and close this window with just one hand! Many Thanks, Allan
