Sash top plastic guide

I am trying to replace a plastic guide for my window. I have no identifying part numbers for the sash mounted guide. The plastic part measures 1 3/4" by 5/8". I have attached 3 pics with as much detail as I could get. The window is hung with the 31" Series 385 Channel Balance and a 15-004 shoe and a 19-005 top if this helps. The window is a white vinyl non-tilt window. Any help would be greatly appreciated. Thanks, Judy