In fact, KVN 3500S had a bigger engine from GAZ 12 ZIM - 3.5-liter inline six, hence '3500' in the name, as opposed to the earlier design with 2.5 Volga engine, being referred to as 2500S. Still, the car is basically the same as 2500S.
The history of those Kosenkov's sportscars is rather complicated and quite foggy at the moment, at least to me, due to a certain lack of information on that period. For example, together with the cars which are usually referred to as KVN 2500S/3500S there has apparently been another one built in Moscow on Kosenkov's blueprints. Moreover, those cars have been rebuilt during their life. I hope it will be possible to trace the life of each chassis one day.
