Broken side piece. No clue where it started

Hi guys... I need help... I also have a broken window.. Maybe you can help with the window ? Years ago (maybe 10) a little metal thing fell out of the track (Side) and the window got heavy.. The one on the other side fell out.. then I couldn't move the window at all(I'm 5'2" and 85lbs) Hubby is gonna get around to fixing it.. Well, he died last year and I still can't open the window.. My son helped me take the window out (tilting) where the little white pieces fell out... Looks like some pieces are missing,(but I pieced it together like another I saw on your site..

The spring part has a red tip (20")and works but I probably should replace it all..

The only part I know where goes is the round piece fits on the peg at the top of the window... which are also rusted..

I think what I need to know is, what is the white thing ?(Shoe?)

Were the little metal pieces once part of that ?

I found another part of the broken piece (I believe is a shoe...) It has PAT. 3.055.362...
I also just noticed a small number 5... The picture is upside down for seeing the numbers.. So if you are looking with the numbers right side up (My picture rotated..he number 5 is abuve were the T is for PAT_ Thank you again i

Will 26-040 work with the 15-015 ?
Should I replace the spiral balancer at the same time ?
How would I know if anything is wrong with it ? S600-20

The spiral balancer tubes seem to be fine..
I ordered the parts (15-015, 26-040 and a charging tool for tilt windows)on Thursday and they arrived by Saturday. You guys are awesome.. The pieces all went in with a small amount of persuasion... And I now have a working window where I just had a window that I couldn't move and a bunch of broken pieces !!
Thank you VERY much for the help and FAST shipping !!
I have no idea how I found you guys.. I think U Tube, but you are now the ONLY place for windows, doors, screens... Hell with Home Depot.. Their solution was to replace the window !! All for less than $20 (Incl S&H) My window works perfectly !! I will recommend you guys to everyone..!!
Thank you again !!
Kathy