Ouch!!!
I had no idea that you had run into so many dead ends nor that you had made so many contacts outside this Forum.
But I guess that this is probably how you found the Forum in the first place


My caveat that I know nothing of document collecting/collections will have to stand me in good stead.
So, maybe this Forum and perhaps a few others like it should be your "home' so to say to try to piece together the whole history of the two sides of the family (Do I have that right?) where you are amongst others who have no financial or idealogical motivation.
Seems to me that goal #1 is to get it all sorted out by the earlier mentioned timeline, get as much translated as you can and assemble it as completely as you can as an historical document. If your family wishes to have it, you can pass it on, if not I really don't know what you can do other than find the most suitable place or places to pass it on to.
I do think that my earlier thoughts on trying to find and contact the military units involved in the information you have developed so far may be a place to pass that part of it on and the school may have a following that would be interested in that documentation.
I do have a similar situation in that my children and grandchildren have no interest in my Dad's stuff, too much of a generational gap I guess. The Marine Corps History Department is interested, but like you I fear it will just go into a void of millions of images that may not see the light of day.
For my part, I intend to pass on those images and whatever written materiel that seems interesting via postings to Forums such as this one as I know there is an audience that appreciates it.
Get er Done Girl
Bill