With all due respect to Mr. Alt and his own work, I find many things to question. Incidentally, while it is true he is a member here, he has posted exactly twice, both times in relation to these negatives.
One thing that I have learned is anybody can be regarded as an expert if they have expertise in a field, and different "experts" often reach very different conclusions. Scientific studies often reach conflicting results. Most folks are aware of how experts hired by one side or the other in a trial seem to arrive at conclusions favorable to the side that's paying them.
One problem here is, what constitutes an expert? Mr. Alt has long experience in large format and ultra large format photography. Does that qualify him to authenticate Ansel Adams? There are many LF and ULF photographers around who may be very familiar with Adams' work, but does that in itself qualify any one of them?
I have for over 35 years used the same type of camera and film that Ernst Haas employed, but I really don't think I could be called upon to authenticate a Kodachrome slide as his.
I see several questionable conclusions claimed as "facts" just in what is in the statement above. Circular logic is being employed to at least some extent.
"Shot on 6 1/2 X 8 1/2 glass plates with a Korona as confirmed on page 3 of Ansels book Examples."
Are they confirmed to be from a Korona? If so, are they confirmed to be from Ansel's Korona? Could they have been from someone else's? How many of those were made? It appears from my limited research that the Korona cameras were made for around 12 years in four sizes, of which the 6 1/2 X 8 1/2 was the smallest.
"Several images have fire damage due to his studio fire in 1937"
The claimed fire damage is proven to be from his studio fire in 1937? Circular logic. Should have put the word "possibly" in there. The statement shows something of Mr. Alt's mindset in this case.
"Virginia Adams handwriting"..."confirmed by independent analysis."
Could be, but handwriting analysis is not infallible.
An experience I had: I once took a camera in to a local repair shop to have a malfunctioning shutter repaired. The technician wrote on the invoice that he could find nothing wrong, and probably a film chip had caused the problem. I was amazed to see that his handwriting was a like a carbon copy of my own sloppy, klunky handwriting. I'm no expert on handwriting, but when I first saw it I was baffled why I would write something like that on the invoice. As I stared at it I realized it had to be the technician's writing, but only because of what was written.
Had it been something I might have written I would have authenticated it with no doubt in my mind. I'm no expert on handwriting, but I know my own when I see it, though from that experience I learned that doesn't mean I know for certain it's mine. My own personal experience makes me leery of "expert" handwriting analysis.
That does not make the conclusion regarding the handwriting invalid. But look into handwriting analysis as a discipline. It is not a widespread academic discipline. It appears to me that a handwriting expert is an expert in no small part because that person says so.
As to fallibility: remember the CBS phony document scandal about George W. Bush's military service that ended up costing Dan Rather his job? The purported signature of Bush's commanding officer on the phony documents was declared genuine by Marcel Matley, one of the two "handwriting experts" employed in this case. Google them both, read what's out there, reach your own conclusions as to the strength of the authentication.
"Lastly, one of the plates are an almost exact match to 2 5X7 images..."
"This is an image of a Jeffries Pine and close examination show the distant snow pack to be identical, meaning these images were taken moments apart."
Of course, it's a Jeffrey Pine.
First, the images are far from "an almost exact match".
Second, how does a distant (no less) snow pack being identical in two separate images prove that they were taken moments apart?
I mean, snow doesn't melt that fast. They could easily have been taken in say, the same week, depending on weather.
Every year, the distant snow pack I can see from where I live looks the same, because the pattern of dark and light is formed from enduring physical features. When it melts off the same pattern is revealed through subsequent weeks. But I've never been able to look at a distant snow pack and see the pattern change within moments. Really.
"Lastly, (once again) these negs were found in LA after Ansel was here in LA teaching at Art Center."
As I recall, Norsigian says he was told by the seller that he got them from a warehouse sale in LA in the 40's. That has not been proven. If true, how much does that add in the way of circumstantial evidence? It places the negatives in LA somewhere around the same time as Adams was teaching in Pasadena. Even back then, Los Angeles was a big place, and there were a lot of warehouses and a lot of photographers. I have no idea how many LA based photographers photographed at some time in the Sierras, but it was probably more than a couple.
"I believe he brought them down as teaching tools."
Possible. That is an opinion with nothing to back it up except some plausibility.
He apparently did not bring his most prized negatives down as teaching tools, or if he did, he took them back, apparently abandoning these. If he valued them, why did he leave them behind?
Now, for just a couple of the claims in the Final Report linked to earlier:
Heading, page 9, (Claim #2)
ONE OF THE IMAGES IN THE NORSIGIAN NEGATIVES IS VIRTUALLY IDENTICAL TO AN AUTHENTICATED ANSEL ADAMS PHOTOGRAPH
Far from virtually identical. Close to the same main subject size, but taken from a different angle. Look at relative positions of background features and the groove in the rock to the left of the tree. Clouds are different. The sun was at a lower angle in the known Adams negative, as shown by the position of the tree shadow over groove. The two images could not have been taken within moments of each other, despite Mr. Alt's claim that they were.
As to the claims of the meteorologist, well, he obviously smokes only the good stuff. Cloud height and snow pack= same day?
As to the relative technical and compositional quality of the two images, well, I know what my opinion is.
Heading, page 17, (Claim #8)
SIZE OF THE NEGATIVES ARE UNIQUE TO ANSEL ADAMS
I didn't know he built and kept for himself all the cameras in that format.
I won't bother to address any more. Even if those negatives were made by Adams, the obvious flaws in just a couple of the claims invalidate the Final Report as an authoritative document.
No, they want to be right by inuendo and vague references. 
