Clips on windows that push down channel balance

The top corners of my Alacan windows have tabs that push down the channel balances, which are like your Series 380. One of the tabs has broken, so the channel balance stays up when I push the window down.

These are plastic tabs that look like they could be replaced. Is this a replacement part you carry?

Two photos attached: one of the broken tab and the other is a tab I removed from another window.

Thanks!