Pivot balance shoe

Hi, I'm trying to identify a pivot/balance shoe from a double-hung window so I can order a replacement.
Markings on the part: "15L" and "075" stamped on it, along with "PAT PEND" text molded into the plastic.
Measurements:- Length: 2 3/4"- Width: 1"- Thickness/depth: 5/16" (7.8mm)- Balance type: spiral rod (twisted metal rod inside a plastic sleeve/tube)- Balance tip color/shape: white plastic sleeve where it meets the shoe
I've attached photos showing the shoe in the window track, a close-up of the stamped markings, and the spiral balance it connects to. Could you help identify the correct replacement part number?
Thanks in advance for your help.