Thank you for the additional pictures. Especially the side view of the BH guide plates. Looks like it is for horizontal buttonholes. The patent looked like it could be either, but since the plates are connected maybe not.
I finally found patent #114598 for the button-hole cutter.
I've thought that some of the tatting shuttles would make nice creasers, too.
Nice find.
Janey - Neat people never make the exciting discoveries I do.