www.p38forum.com
post in the postwar P38 section.... "need date info" and either Orv or Dieter will answer you....
be prepared to give full serial # for this info....
I can tell you that production began in 1963 @ serial range 200.000
serial #'s go up to 450.00... though they are intermixed with P38/P1 as all P38/P1 were made in Ulm by Walther... the P38's only went to Manhurin for proofing and "marking" so they could be delivered to West-Berlin