Metal bracket for Series 400 balance

I need to replace two spiral balances in a non-tilting aluminum window about 20 years old. I have identified the part needed as S400-30 green.
However one of the lower brackets is broken, half of it fell out of channel during my investigation.
I see that you sell brackets but they don't seem to be accessible for replacement.
Question. Assuming that bracket cannot be replaced, how well would the window work with only one balance?
We are tired of using wooden props.

Looks like this will work. I will need to make a small revision to the frame. Will send results later

Installed an aluminum channel in the window sash and attached the bracket.
Your installation video says to charge the balance using the tool turning 2-3 turns. I have tried 2, 4 and 6 turns and the window only holds half open.
Do I continue with more turns or will I damage the balances?

Success. Using a hint from another email from Swisco I found that the sash weighed 23-26 pounds which showed that I was using the correct replacement part.
However it took many more turns than noted with the charger to get the window to stay wide open.
If the balances fail from too much tension I will replace them with some from a window we never use.
Thanks for the help.