Martin Rocks, Love my D18 soooooo much. Sent you an email.
Eko.

Going to take it there tomorrow or Saturday. (I have to sub calculus on Friday)
The guy I talked to said that it's not a certainty Martin will approve repairs, but his "gut" tells him will.
I have a 6 string Martin DC-28E. And, I've got my B-i-L's Bob Shane model, too. Nice guitar. Ugly as sin.
We'll see what happens. I suppose.

If so that is the ugliest martin I've ever seen. What was wrong with the 12 string?

Sort of. Some had a pickguard above & below the soundhole.
40% of the top is black plastic! 60s spruce top and we can't see it.
It has a different tone than mine. It's a bit more midrangy. Mine is from the 90s, so over 30 years the woods may be quite different.
But, we agree for sure on what an ugly guitar that is.

The link shows that model in the upper left. Was Shane using a garden rake for a pick?

approve the work it needs! Very good news!

Took my guitar to the authorized repair place.
First, I have to say it's quite a store. Aside from one Les Paul on consignment and a few archtops with pickups, everything is acoustic. Guitars, banjos, mandolins, fiddles,....
Anyway, the luthier was actually there. He looked at it for a good 10 minutes. He told me "I've never seen anything like this before."
Using a mirror, they could not find the coupling that connects the threaded rod to the adjustment lug. It's either missing, or it's set so deep the lug threads can't reach it.
Since I only play that guitar occasionally (especially now with the bad action) I told them not to rush.
We will see if Martin will cover the cost or not, but at least now it's in the hands of an expert their company authorized.