New Old Stock Delta Pulley Half Sections for 31-425 Backstand Idler Unit.  Part number 406-01-062-0002.  Sale is for 2 pulley halves for 1 set.  Halves have been stored loose, and may have some warehouse dirt and light oxidation, but are fully functional.  Each section is identical, and is 5-1/4" diameter by 2-1/16" wide, finished width is 4-1/8" with both sections.  This is known as the wide set, I also have narrow halves available.  List pice $162.20 per half.