Thanks, very interesting. The split on the forward end of my example doesn't look like impact damage, do any of the Polish smokes have a low-explosive dissemination charge?
This is the only one matching. You can even read DGN on Your specimen. The manual aso describes that the soldier simply inserted thhe RDG into the chamber of the DGN. As the RDG-2 is made of paper there are no tight tolerances possible. It is not obvious from the drawing but the two halves might be "spring loaded" to hold the RDG-2.
Bob