Don,
There is no pin in the left knob of a dished toggle knob. The axle pin of the toggle joint is retained by the toggle lock. Since there is no toggle lock on this piece, the axle pin is only a friction fit just like the forward toggle link to breech block pin. Did you also notice that the toggle is blank, no DWM? And, it appears not to have been milled down. I repeat, this is a strange piece.
Ron