You might want to pick up a copy of Mike Fletcher's
Early Aircraft Drawings 1911-1919 CD. There are dozens of Farman drawings, and several pre-war types are included. These are mostly drawings from Flugsport, Flight and other period publications - some are next to useless but others are quite detailed and well done. All in all, it's a very worthwhile $32.
There's an HF24 on my to-do list. . . . .