I need to purchase some window parts

Hello,

With this combination of attachments, you could have either an S380 or S385 channel balance. You’ll need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment. 

You'll also need 2630 spring strength options for your 27" replacement balances and 2030 for the 21" balances.

As for your top sash guide, we don't carry an exact match but you may be able to grind the top off of something like the 18-009 if the dimensions match up to yours otherwise. 

Thank you and let us know if you have any other questions or concerns.

Comparison of the S380 and S385 balance shoes.