I do not want in any way to step on Ropat's toes but I can add some more here that may help.
The manufacturer, as Ropat states, was called PZInz and I cannot translate that well but sort of "Polish Manufacturing Company" is a good approximation.
The field car versions, "Jeep type" bucket seat vehicles, were variously identified as "Polski Fiat 508/IIIW" and later with a larger motor, "Polski Fiat 518/T".
As I understand the Google translation of Polish, the field cars were called "Lazik", and the truck versions such as the telephone truck in the puzzle photo, were called "Mazur".
I am not looking for a point here, just trying to clear up the puzzle as best I can with what I know.
Bill