I’m in the camp of retain the originals obviously but try to source a new pair along with a new magazine because I would be inclined to shoot modern weak sauce ammo through it just because. Then display it prominently with the original parts. Oh yes. Nice gun and great story.

I'm in agreement with the other members not to do anything to the Sauer38H, holster and ammo than preserve it in its present condition and document its WW2 history. Also recommend you check with family to see if there were capture papers or any other supporting documents. This isn't a range/target pistol, I would not fire it. If you have the original ammo from the mag retain that also. Is there a spare mag in the holster?