I think you're overlooking the mahogany neck.
I'm pretty sure a D-44M has a maple neck, and a D-46 would have an ash neck. I don't know if they made G-37's with a mahogany neck. I do know that my G-37 is maple.
The D-30s were introduced in '87... so had snakehead headstocks (?)...
We just worked G-37/D30's to death recently,
here
Yes D30's got snakeheads.
G-37s got 3-pc maple necks and chesterfields ca '75-'76, 'hog prior to that.
Didn't look at vid but assume it's not possible to see soundhole to check for bracing which would confirm or eliminate G37 or D30, since everybody who posted knows enough to do that.
WELCOME ABOARD, PLEIS!
G37/D30's are the essentially the same model, just got renamed in the '80s.
They have arched maple backs, and thus no back bracing.
So if you can determine if the guitar has bracing that would eliminate those 2. If it does, then it has to be one of those 2.
Ahh, I see Gardman has eliminated G37 based on headstock while I was composing this.