clasp help!

[A Breaker]

I am trying to understand this clasp...it is vintage...but how does it work? Would it be adjustable? While I am asking..would these be dyed?

 

[ennui]

Do the clasp pieces pinch open? I've seen adjustable clasps that appear similar, it pinches and you can clasp it over a pearl.
But my first thought was that there's a piece missing. Where did you find these?

 

[jshepherd]

I think they clasp over the pearls as shown. This would make them adjustable. If only using one and tying off the end of the strand, it could also be used as a lariat I believe.

These pearls look like they could be natural color.

 

[BWeaves]

Rene' Newman shows this clasp in her Pearl books. It's infinitely adjustable, because you can clasp it over any pearl in the necklace, or leave it hang like an end bead.