My contact in Italy has this to say about the two Artenas:-
The Czech car and the car at the Automotoretṛ of Turin are part of the same commission. One year later the end of the production, in 1940, the Ministry of the Defence needed a 2 liter car to assign to the Headquarter offices, so they commissioned the sedan (with and without the internal dividing) to Pininfarina, the torpedo to Viotti and the ambulance to Bertone. Meanwhile Viotti developped also a tactical vehicle, the trasformabile, for the Royal Army. All the cars were based on the IV series chassis and the trasformabile had also a different gearbox and a bigger tank.
He also mentioned this very nice original car for sale in Italy,
http://www.autobelle.it/annunci/dettid.php?gb_id=128121The price seems very reasonable, especially when you consider the costs involved in restoring either of the other cars!