The actual plane appears to have been considerably smaller than the artists renderings.
The "clean, sharp" pictures with 12 tractor and 6 pusher engines are fake
The fuzzy photos with the 6 engines on the leading edge and a single pusher on the trainling edge is the real small K-7 which flew in 1933 and broke up in-air in its 9th flight.
NB "small is relative. With 53m wingspan and 40 tons takeoff weight it was pretty much the same size as the ANT-20 Maxim Gorky