Odd end on this sissor gate - what does it attach to on a candlestick?

[Vern P]

Picked up this sissor on my last "kissing frogs" trip. I have seen these before, but don't know "what goes" in the end.  It slides into a "keystone" slot.  The one I got has a home made "keystone" piece.  Anyone know what would have gone into this ?
Vern

[Vern P]

Still looking for "what goes on the end of this". Someone must know, please help.
Vern