Ok, only four... I go slowly. But the fifth looks very interesting :
Similar model is shown by Watch22, here, and by pmwas here
Gold plate symbols are discussed here
Mark Gordon (Welcome to USSR Time!) shows also a similar Poljot-Rodina with same inscription inside the back (61-3-3) : Images for ID: 0887
:think: But I did not find any reference to a movement ( 2415a ) with this gold engraving inscription...