Hi Juan,
What is the serial number on the front of the frame of your gun, just above the trigger guard ?
Here is a previous discussion with info. on the "MP" stamping :
http://forum.lugerforum.com/showthre...5&highlight=MP
BTW...the Portuguese holster for their M943 model (your holster style) can be found with 4-digits stamped in the leather....Not sure if that stamping is for a gun serial number (SN) or an issue/property number