Is changing the cradle my best option?

Van came from upstate NY lot of rust. I was recently changing the control arms CV shafts tie rods and struts. I had to lower the sub-cradle and no problems until I removed the subframe bolts and bushings. One snapped off and broke whatever nut it screws up into in the subframe or wherever it goes and the other took out the thread with it, so it won’t thread back in. I had already anticipated it and got new bolts and bushings, but they are useless as it stands. The cradle is being held up by a chain right now so the rear doesn’t sag and put pressure on the rack and pinion linkage. I have access to a less rusty donor van. Is swapping out the cradle the best option? Only option besides a weld? What does the swap entail?