Simonton Casement Widow Replacement Parts

I need everything that goes on the bottom of this left/right pair of casement windows to make them operate. The real issue is the totally rusted guide bar - and in most cases the piece it ties to - you can see from photos 9 & 10 the old guide bar is rusted around the clip the bar is supposed to attach to. The same is true with the clips in the windows themselves which we can't see. I could just replace the guide bars - but while I am in there maybe I should replace the operators also?