I also have my Dad's WWII P38 bringback..It is a AC44 ( Walther) All numbers match as does the magazine..
I also ran across another P38 and snatched it up, it is a BYF43 ( Mauser)..Those who have WWII P38's might like this info..
http://www.pistole38.nl/tech/P38ProductionDates.pdf