Reset time! I've learned to sing the song "Closing Time" substituting the words "reset time" and it looks like this may be your favorite song for a spell too.
Can't remember for sure on the DMs but I think that they have that single bolt glued mortice and tenon joint. Hopefully the glue joint has already failed but if not some steaming is in your future. I think that these have a wooden plate over the neck block covering the bolt too. The plate is only held on with double stick and a very small spatula works great to loosen the plate.
We have a special tool for these Martins that Dave also invented. That Dave guy sure gets around I tell ya....
Anyway it's brilliant and especially engineered to steam the necks off Martins with this specific neck joint.When you get to this point Wud give me a call at Ann Arbor Guitars and I will be happy to tell you how to make your own with about 99 cents of hardware likely from your own store.
Lots of bracing may be loose too from your excellent pics. If you have an IPhone you can shoot video in the box for later display when your comfortable and with a beer. Pushing in and out of the top with one hand as you position the camera with the other hand can help to reveal the extent of the loose bracing.
I have to hand it to you too Jim and this is as sincere as a heart attack. You've gone a different route then most here seeking out these basket cases and then carefully and lovingly restoring them to playability and doing some really great work too I will add.
You will know far about how guitars fail as a result and as such likely will be able to put this to good use building too.
Good going my friend!
![[:Y:]](./images/smilies/smiley20.gif "Thumbs Up")
This repair/restoration stuff is interesting and I like but it sure can be a challenge sometimes and nothing at all like building a new guitar. Of course, I know you'll get 'er done Wud 
Great Idea