Window hinge "locks" in the upper window hinge (1970s)

[lojoma]

I don't know if this applies to other decades so I put '70s in the title.

On each end of the upper window hinge, there is a riveted piece that acts as a lateral "stop" for the window. You have to get the window between these to install the window.

Do these things have a name, and if I need one, any idea where to get?

Thanks!