Channel balance part replacement

Thank you for writing in your question. Starting off with your top sash guide, our 18-171 looks to be compatible with yours. Look it over to confirm the measurements are a match. For your balance, either our S351-27 and S390-27 may work for you. You will need to measure the depth of your bottom balance shoe, like in the diagram below, to determine which balance would make the better match. Whichever one you choose will go with a 2640 stamp option that holds a sash weight of 19-26 pounds.  

Comparison of the S351 and S390 balance shoes.