Hello Paul, I'm working on a enigma replica(the German encryption machine of WWII). I'm building it only for fun and research, because when I have finished it I will improve it a little bit, and in a future I will connect to a server and talk with my friends within this machine and its encrypted messages. Discussing about the size, I don't have any preferences, not too big or too small, more or less like a normal keyboard. Thank you for your attention.