Order of Polonia Restituta: Pre WW II 4th class; PRL (communist) 4th class issue; PRL 5th class.

Reverse:  Pre WW II type; PRL communist type 1944.
WW II Exile and current issues also have 1918 on the reverse.  Copies are now in circulation in substantial numbers.  Rare pre-war versions made by jewelers for private purchases are un-common and worth a premium.