Proposed SU-85 Modernization

"People's Commissariat of Tank Production
Order of Lenin, Order of the Red Banner of Labour
UralMash Factory

To the Chief of the NKTP Technical Department, comrade Frezerov
CC: USA GBTU Chief, Major-General comrade Alymov

RE: carrying out order #550s

In carrying out order #550s issued by the People's Commissar of Tank Production on September 17th of this year, we send the following materials for approval:

1. Assembly blueprints of a reinforced gun mantlet mount for the D-5 gun in the SU-85 SPG. The blueprints are sent simultaneously with the order to begin production. The reinforced gun mantlet mount will enter mass production starting in October of this year.
2. A proposal of a commander's cupola for the SU-85 in two variants:
1. First variant: installation of a cupola on the existing SU-85 hull with minimal changes (cutting a hole in the roof and side, a special cap, etc). In this variant, the commander's cupola could be quickly installed in production.
2. Second variant: installation of a cupola widened to the width of the tracks while maintaining the front plate. This variant was developed by UralMash factory only as per the conditions of order #550s."