I am glad to see this archival material readily available at the site referenced in the OP. My first steps out were a deep reading of much of this same information. I purchased a number of books which at the time were republished by a Bible Student group in Chicago.
I am a bit curious though about this site www.pastor-russell.com . It seems odd they state they were the first to make this material available online in 1997. Well, maybe online, but I had copies of the same things on my shelf back in the '80's. Then they caution against downloading the material anywhere else, as they are the only official source. But much of the material was not copyrighted or the copyright has expired, so there is no official source. They have watermarked all their downloads, the purpose of which is unclear. They even have the audacity to put up scans of the 1975 yearbook and the 1993 JW history book, which <are> under copyright by the WT society, and they put their own watermark on that too.
I appreciated what they have done, but something about it doesn't smell right.