"To the Director of the Kirov Factory, comrade Zaltsman
CC: Chief of the GABTU, Lieutenant General of the Tank Forces, comrade Fedorenko
CC: Chief of the GAU, Colonel General of Artillery, comrade Yakovlev
Following government decree, we produced two experimental prototypes of 107 mm ZIS-6 tank guns and began mass production. According to the decree, we installed one of the two prototypes into a KV-2 tank and conducted trials, the second prototype is to be installed in a KV-3 tank.
Due to a delay in the mass production of the KV-3, we propose installing ZIS-6 guns into the KV-2 tank.
In order to reduce the time spent on developing the mount, we send out blueprints for the frame and mantlet developed by our factory for the ZIS-6 prototype.
Attachments: blueprints and specifications on 4 pages (only on the copy sent to the Kirov factory).
Factory Director Elyan
Chief Designer Grabin
July 22nd, 1941"