I believe what you want it a binder or binding foot. A vintage one might work if leather is right width and fed into the binder evenly. There are some vintage bed mount binders that would probably work, too. Then there are modern ones like
https://so-sew-easy.com/use-binding-foot/ and
https://www.sailrite.com/Sewing-Mach...-Parts/Binders
Janey - Neat people never make the exciting discoveries I do.
Not affiliated with off-site link(s)