Spiral Balance w/attached shoe.

Hi,
I'm trying to find a replacement for this spiral balance. It's 23" x 3/8' with a red tip. It has an attached shoe that is connected with a rivet and the whole thing pivots a bit. The shoe is nylon(?) but it also has a aluminum piece that is used as an attachment to a spring loaded quick release located on the bottom corners of the window itself. These aluminum replacement windows have no identifying markings anywhere and are maybe mid 1970s-1980s. The only identifying mark I can find is on the bottom of the shoe and it's a US patent #3,688,441. There is a very good side view technical drawing from the patent on Google Patent search here: https://patents.google.com/patent/US3688441 (Fig. 11 & 12) plus I've attached a few pics.

I would appreciate any help at all with finding a replacement spiral balance with an attached shoe for this.

Thanks,
Ken

Thanks so much for the help Paul! Looks exactly like the one I have. I ordered the part from you guys. Your prices and shipping are very reasonable. I see you're going to be closed tomorrow because of the Nor'easter. It's 75 degrees right now here in central Florida. I feel for you man.

Thanks again,
Ken