This parts kit was a kit we designed when we were a Ljutic Dealer. Necessity Kit contains: Ejector spring, hammer spring, inertia lock spring (opening button), trigger push up spring and smallest is for release hook lift spring. 3 pins, front bead, cocking rod retainer pin and firing pin retainer screw. This kit is $135.00 incl s/h to lower 48 states. Shoot well!
That's a tough one. I've only seen one crack in almost 50 years.. If you still have the pieces, I'd find a retired machinest that could start with that. Each one is a custom fit, so that would need to happen. You could call Irwin Industries in Yakima, Washington area and see if they sold the parts inventory to someone. Good luck.