Thanks a lot Jim for your kindness and for the precious help!!! When I purchased that 940 I declared the serial PKN as it seemed to me (and as stated and registered by the previous owner that sold it to me).
Since I am almost fifty I am gettin' scared my eyes could have played a nasty trick on me.
The first time I'll take that 940 out of the safe I will examine it very carefully and I really hope I did no mistakes