Caldwell balance

One of the balance pulleys broke apart, snapping the line with it. The other is slightly bent from constant use over the years. The marking on the balance is 27 3 KO Caldwell....The channel is 28" in length minus the plastic pieces attached on the ends. It is 9/16" deep by 5/8" across the open end of the channel. The channel also has folded over edges. I would like to order two balances with the plastic ends attached and with the hardware required to attach them to the inside of our aluminum doubled paned window....I wasn't able to take a picture of them. I will ask someone to do so unless you already have a pretty good idea of balance described.....