For Death Mountain I found an image on google that was gigantic resolution. In fact what I have as Death Mountain is just like a side of the image I used, not the full mountain, it was a really big picture and I wanted to squeeze as much detail as I could out of it.
EDIT: As far as the old beta of Zelda goes, no, it is not possible. First off, look at the screens, the things that do have texture have horrible shitty textures. Second, there is no rip of these, I wouldn't even call them betas, more like alphas. I doubt the code was even written to cart (if it was it's probably somewhere on a shelf in a Nintendo archive or in a box in some coders house).