You can now review the professional papers of Liberace’s former publicist David Epstein who passed away in 1970 courtesy of the Rocky Mountain Online Archive at the University of Wyoming. These papers must be examined in person.
Liberace’s materials are in box 3, 9, and 31 which include his client file. Details about the complete Epstein collection here.
I find it interesting that Lee appears in two sets of personal papers held by the institution. Yet another example of how you just never know where his legacy has traveled.