Old fancy clamps

[coolford]

I recently cleaned out my "C" clamp drawer and got rid of many of them.  These were also in the drawer and I figure they are old.  However, they have no markings of any kind.  Neither are they similar, the screw in each is a different diameter, thus they are not interchangeable.  Anyone know who might have made them?

[leg17]

Inexpensive clamps for quilting frame.
The girls might be more interested then the boys.

[amecks]

I believe these types of clamps may have been also used to clamp the sewing machine to the table.  Singer made similar clamps.
Al