You would actually want the crack to be open. Welds shrink and you want the end product(when it cools down) to end up where it is suppose to be. You can't just weld it as is. The crack has to be V'd out so that the weld fuses into the hinge pin hole. The cocking rod holes will be totally filled. After welding it would have to be annealed again, then you could redrill the cocking rod holes and ream the hinge pin hole for a new pin. File and shape the frame,pollish and case harden. PROOF TEST and hope all your work wasn't wasted. I think it's possible.
