Replacement part for Stanley Double Hung WIndows

I built my house in 2006 using Stanley Double Hung Windows.
Recently a number of the windows have had failure of the metal piece that insert into the tilt carriers located on each side of the window frame. The insert is about four inches long and is U-shaped. As shown in the pictures it protrudes from the bottom of both sides of the tilt out window and mates with the tilt carrier. It is secured onto the window by one Philips head screw.

I need 24 pieces