Часы Урал ( Молния 3602) / old large soviet URAL watch with Molnia 3602 movement

This watch is made in 1957, or actually only the case and dial. The original molnia 15 jewels movement was completely rusted. I replaced it with more new (70's?) Molnia 18 jewels pocket watch movement. The new movement is more thick and the back cover won't go completely down. Also the stem is too long and has to be replaced with shorter one.