Question about No 1 Mk I firing pin

[Bear43]

It should actually be one raised lug on the striker. If you look at your bolt head it should have a notch in it as well. If you turn the cocking piece so the striker is full forward that notch in the bolt head will fit on the lug on the striker and allow for turning it out. So long as it will break loose from the cocking piece anyway. Early Mk III's were like this as well.