The libraries were open to all up until 1980 when the Bethel library was moved from the 10th floor of 124 C.H. down to Squibb. The Bethel Library was the one used by the Writing Department, so it had all the major commentaries and ALL (multiple copies, too) of the old books, booklets, magazines (Wt, Golden Age, Consolation), Food for Thinking Christians, Informants, Messengers, KMs, songbooks, Rutherford's legal books, transcripts of court cases -- everything. (Russell, Rutherford, Quackenbush, Cole, Moyle). It was moved to Squibb supposedly for the renovation of 124, but no Bethelite access was allowed at Squibb. It was now for the Gilead and Writing use only.
The 107 C.H. "Gilead" Library was good enough for me, it had many of the old publications. But it had almost no commentaries, and it also contained a lot of "fluff." Subtly, the old valuable stuff was removed. Rutherford booklets and old tracts were moved along with most of the older Russell related books started moving out. I left in 1980, so I don't know exactly what finally became of the 107 Library. I assume it's still around (maybe in the Tower now?) for Bethelite access. But I'd bet there are less Bible translations, no commentaries except maybe the innocuous Barnes and Matthew Henry, a limited number of old publications, and plenty of less embarrassing recent publications. Things may have changed again by now, I only know how I left it in 1980.
There was a small library on the second floor of 107 for immediate access to Bro. Glass' classroom, along with fairly good reference libraries in the offices of some GB members. I was never caught by the night watchman, but I used to lock myself in Bro. Glass' classroom, sit on the floor behind his podium to read his Gilead Notes. I didn't know at the time that Bud, the front desk guy at 124, would later be able to get me my own "student" copy (for a price).
What a waste of time!
Gamaliel