Odd Twoonie Core

The normal core planchet is indeed smaller in diameter than the hole. It is also thicker than the ring. The striking creates the locking mechanism that, in the Canadian planchet, looks like: ((---)). (A paper explaining the differences between the German and the Canadian planchets is currently being reviewed - it will be sent to the CNA journal including pictures of the planchets)

I think, a side view of this core would look like the planchet was folded as a Z, or more probably 2 sheets were supperposed. Bucking probably occurred but why the difference in colour? It looks like 2 different planchets where involved. Is this a "retained cap" or a retained strikethrough a second core? (NO! I will not try to wedge a knife between the 2 sheets! Don't even think about it)