Channel balance

Hi! I have an inoperable window. Manufacturer is unknown. AAMA certification sticker identifies them as manufacturer PHP-07. It's a TILT single hung window. Series 810. The window was installed in 2005. It's obvious that the pulley on the channel balance has failed. I need to replace the part, but I need to be certain that the part is the correct part. Please advise. Thanx!

Addendum: I removed the channel balance. The base as well as the top were broken. Please refer to the photos. The markings on the opposite jamb are identical. That channel balance on the opposite jamb is working fine.