Windows will not stay up

I have some single hung tilt windows that will not stay in the up position . upon inspection I found that the pivot shoes on most of the windows are broken where the hooks would go to attach to the spiral balances ( would need 5/8 600 blue tip). It seams that most of the spiral balances are ok and just need to be recharged. This seems to be typical in most of the windows in my house.

How do I determine which pivot shoes to use?(aprox. height 2 1/2 in, across 1in , depth1/2). Where the incorrect ones installed by the company? The part where the window inserts is blue and is intact, but the plastic part near the top part, under the metal piece where the spiral balances attach are broken. The windows were put in when the house was built. I think the brand is Alcoa made around 1994?? It seems that this might have been a problem with these windows?? Your help is needed.

Was unable to remove the pivot shoes. There was no notch in the frame and I do not have the special tool. The aprox =width 1in., the thickness 1/2in. This is a picture.