Alcoa spiral window balance part identification

A quick learner from Ohio says:
I've got an Alcoa window that won't stay open and wanting to purchase new window balances.

I've taken a couple shots of it and attached them. The plastic cover is off in the pictures, but it can bee seen to the side. I've also attached a picture of the pivot shoe, if you think I should replace that as well.

On the balance, I measured 28 3/4" long and a width of 5/8". Can you please help me decide which balance I will need?

Thank you!
User submitted photos of a spiral window balance.
Profile picture of Tom
Tom from SWISCO responded:
Thanks for posting. I recommend that you consider our Series 600 spiral balance and 15-046 shoe. Carefully compare this hardware to your own to see if they match.
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