Casement window crank arm - black glider piece that fits into track

The brand of the casement window crank assembly is Truth. The part that is damaged is the black piece and attached metal glide (shown in photo) that ties in the lower hinge of the casement window to the installed to the track appears to be damage/cracked due to use. It jumps from the track. The black piece appears to be marked a part # of "26".

I was able to get some of the part # markings on the other arms of the assembly which were not damaged. These are "30744" and 3Q(or 0?)866.

I'd like to see about getting a replacement for the black glide/hinge attachment if possible or for the overall opener if it is necessary.