Have you tried contacting the guys at Old Rhinebeck (oldrhinebeck.org)? WW 1
is their specialty and they may have a few engine gurus that can help. If not,
you might also try the Naval Aviation Museum in Pennsacola. I know that they
have several Liberty V-12's in their collection, as well as the original
Curtiss NC-4 (on loan from the Smithsonian) which I believe was powered by
Liberties. Sorry I can't be of more help, but my area of expertise only
extends to early Wright aircraft.

Harry Frey
Wright Brothers Enterprises