Thank you for the detailed response, Ric, I appreciate it.
One thing most of us long-term TIGHARs have learned is that the bar for claiming to definitively the solve disappearance of Earhart and Noonan is extraordinarily high as far as the general public goes. And, indeed, as far as the professional aviation history community goes. Preponderance of evidence isn't really going to cut it. Removing all possible doubts is the only thing, in my view, that will enable TIGHAR to make the final declaration and have it stick. We can't do that with anything that has been found to date.
So, since you stated, "There appears to be no surviving paperwork on most of the changes that were made to the airframe. All we can do is carefully date the photos that show the changes" and "As shown in the research bulletin, the change in the specs for Part Number 40552 was effective 1-15-37 so it seems likely, but we can't prove, that all of the window changes were made at the same time in the last half of January 1937," that injects a great deal of uncertainty into 2-3-V-2's provenance. TIGHAR cannot definitively prove, through paperwork or some other valid quantifiable method, that the windows in NR16020 were replaced by 1/8th-inch Plexiglas. You can't measure window thickness by using period photographs, as far as I am aware.
That, to me, removes 2-3-V-2 as having any possibility as a diagnostic artifact. I was prepared to spend my own time, money and effort on wringing the Plexigas dry to show it came from our favorite Electra. I can't justify doing all that if the artifact can be so quickly and easily dismissed, but I'm open to having my mind changed.
LTM,
Monty Fowler, TIGHAR No. 2189 EC