Mystery pivot bar

These stamped pivot bars are only 2-1/4" long. I can find no brand markings on the windows themselves. I'd be comfortable finding a longer alternative and cutting them down, but there's a bit of a taper at one end that goes into the shoe, and I don't see anything like that on your site.

It's 3/16" high, 5/16" wide but 1/4" on the tapered end. Taper makes up about 5/8" of the length.

What do you think?

That's unquestionably it. I wonder how I missed it. I'll certainly go order a few. Thanks.