What are they?

[Kernopelli]

Pattern shears?

Pattern Shears @ SunshineGlass.com

I think you're right. My wife stated she was pretty certain the estate owner was a hobbyist making stained glass.
Thanks!

 

[Pipestone Kid]

Those are pattern shears for stained glass workers. When you cut out a pattern the center blade removes enough of the pattern to allow for the lead came or copper foil (which ever you use).

 

[sixdogs]

My uncle, who shortened chair legs for a living, had a pair like that. He never did get them exactly even but kept trying.

 

[shucksters]

leather sheers with an awl?

 

[glinke]

They are used to cut patterns for stained glass windows. The little strip cut out of the middle is the same thickness as the center part of the lead came that is used to join all the pieces together.