strange p 38 in museum

[mkb42h]

recently in a museum in italy i saw a p 38 marked

'p 38 walther'

on the slide with no other markings but the walther was written staight across, not in the banner. i t seemed to have commercial proofs on the trigger guard but no wehrmacht proofs. it had no bulge under the trigger pin and had military style grooved black grips and a 5 or 6 digit serial ending in 'm' on the frame below the p 38 marking. the finish was a very nice polished blue.

i suspect it might be fake but it looked very real and all the other pistols in the case were clearly real. any ideas what this was?

[mkb42h]

actually having done some research i suspect it was a mid to late 0 series with a postwar engraved slide so it could be sold/traded as a 'real' walther, the 'm' at the end of the serial i think was, in fact, a waffenampt.