Not finding 10" drum spring for 67 GTS

I had the short return spring break on the driver's side. Existing springs are original Mopar. I had a hardware kit that I got some years ago but the short return spring in the kit was stiffer and had a shorter offset so it didn't clear the wheel cylinder like the original. I then tried ordering a Wagner hardware kit from Rockauto that said is was for my car. Wouldn't you know the springs were ok except for the one I needed. Here's the spring I'm looking for:

View attachment 1715014089

This spring goes to the self adjuster lever. It's not a return spring. The return springs are the same, one just goes through the cable guide.