OK, hear is what I think I know. The main difference is a couple of more pins for the intercepting sears. Below is a Charles Hellis 9 or 7 pin lock, depending on whether you count the striker pivot and the mainspring pin. There are 8 pins showing (counting the striker pivot); the mainspring pin is on the front of the bar and not showing.



I can put markers on the pins if questions remain.

IMO, the extra value of the 9 pin lock is whatever value you personally place on intercepting sears.

DDA

Last edited by Rocketman; 06/10/13 11:52 PM.