Hopefully, your second frame/chassis is really in good condition.. Your first one is not serviceable.
Before you do anything else, you should do dry and wet compression tests on your engine... Find out just what you have. Try to discern the state of the tranny and tcase as well
Evaluate the second frame/body... If it's really serviceable, I'd pull the powertrain from the first one and install it in the second one and go from there.
You may find other components in the first one that can be transplanted to the second one, but the body/frame is honestly looking pretty dismal.
If you can take the second as your build and use the first as your donor, you have a good start.
But, since you will be pulling and installing a powertrain, now is a good time to make sure it's serviceable... So you don't have to pull it again to rebuild it.
HTH