https://www.thoughtco.com/body-of-stalin-lenins-tomb-1779977
Preparation for Eternity
Though Stalin’s body had been embalmed, it was prepared only for the three-day lying-in-state. It was going to take much more to make the body seem unchanged for generations.
When Lenin died in 1924, his body was quickly embalmed through a complicated process that required an electric pump to be installed inside his body to maintain constant humidity. When Stalin died in 1953, his body was embalmed by a different process that took several months.
In November 1953, seven months after Stalin’s death, Lenin’s tomb was reopened. Stalin was placed inside the tomb, in an open coffin, under glass, near Lenin’s body.
It’s funny how religious Lenin’s tomb was for atheist materialist marxists.