I just got a byf 44, and want to know what the X over the serial number on the frame means. I have looked all over the internet but have had no luck, the serial # is 7690t. I have broken the gun down and all the serial numbers match, but the colors on the gun are different, the barrel and part of the frame are more grey and the other parts are blue. There are no import marks on the gun anywhere. Can somebody please explain what I have?