PGT Single Hung window balances

I have a PGT single hung window approx. 12 years old. I need new balancing springs and sash guides. I have attached pictures of these parts. From my studying the pictures on your site, it appears I need S385-37, with top 19-005 and bottom 15-004. The balance spring identifies it as 36 5 FX CMC 7. I thought that indicated a 50# window, but I weighed the window at 35#. All measurements seem to fit this configuration. The only difference I can identify is that the bottom nylon fitting on my spring balance does not have the "ears" on the bottom side (hook side) as seems to be shown on the pictures. Could you please take a look at the pictures and let me know if I can just cut these ears off? Also, do the pictures look like a S385 37? Thank you very much!

I sent a previous email, but could not include all pictures.