Window balance.

Hello,

It doesn't look like your top or bottom fittings have wings, which means that you could have either our S351-31, with a 15-002 bottom attachment, or S390-31, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. You'll also need a 3020 spring strength option for your replacement balances. 

As for your top sash guide, I would recommend starting by comparing the dimensions shown on the 18-110 product page to yours. Thank you!

Comparison of the S351 and S390 balance shoes.