Don't know if in right place but I have found amongst my late fathers things a stainless steel object which I don't know what it is.
It is about 2inches long, half inch wide and not much depth, it has on the inside sliding what can be described as a large pen nib which pulls out to be pushed up like a guillotine , on the outside on one side is a round hole and on the other side the corresponding hole is more oval, it is clearly to be used by hand as the top edge has a place for your forefinger whilst you push the inner with your thumb
Any ideas please would be very grateful.