I wonder if they were made like fine Sterling hollow knife handles were made, and then cut lengthwise and stamped? My mom and grandmom both had knife handles that had that look, but the also had Sterling cold cream jar lids and compacts, etc. I have some of the knives in the gun safe. I'll pull them out and inspect them later. If similar, I'll post pictures.
I am certain they were made much the same, Harold. Lots of these items were stamped using dies. F&B made a plethora of items.
Here is a nail file and a dresser jar from them.