That striker system sounds like the concept that Rhino designed a few months back. He put some pics up on that thread.
Seems like a ton of things done to make the FA stuff "not work". Is all of that really necessary, I wonder? Since the -42 conversion requires only 2 things (grind of sear lug on bolt and weld in a block in the receiver), I wonder if all those additional items are necessary.
I've been too busy to work mine lately. I'm very interested in seeing progress on this!!!