Need to replace a broken window balencer

I have a Huntington Vinyl Double hung window made by Kensington High Performance Windows.
Photo 1: Broken Coil Spring, on the darker spring portion note tiny hook that connects to the Pivot Shoe.
Photo 2: Type of Pivot shoe in my window.
Photo 3: Coil housing with the cover removed. Number 8 R printed on the cover
Photo 4: Coil housing photo intact taken on another window. 8 R visible.
Your assistance is much appreciated !