Olddrifter: Sounds like you have come up with a nice old handgun. Although not so old as to not give you lots of fun, as well as an adequate defensive pistol.
Coyotejoe is right - yours was made by Mauser in 1943. I would have a gunsmith check it out just to be sure it is solid and reliable, although you almost really have to kill those things with a tank before they give out on you.
You always want to check the chamber and barrel for signs of extensive pitting. If the chamber is pitted you may be limited to using steel case ammo to prevent a brass case from expanding into a large pit and cause the pistol to fail to extract. If you chamber is clean you may see some pitting in the barrel but this doesn't seem to hurt those things a bit and they retain their accuracy.
One concern for the gunsmith if he/she has not dealth with the P38 before is the firing pin cover on the top of the slide. This should not be removed unless absolutely necessary, as with the wartime pistols they have a tendency to lose their spring tension and they keep falling off exposing the firing pin and loaded chamber indicator. If the pistol chambers a fmj 9mm round and the loaded chamber indicator does not hinder chambering then it works fine and there is no need to mess with it or the cover. To test your firing pin function either take a primed (but empty and otherwise unloaded) 9mm case and see if a full strike detonates the primer. Or, turn the pistol barrel facing up, drop a thin pencil down the barrel, eraser first untiol it bottoms on the bolt face and dry fire the gun; the pencil should fly out of the barrel (caution - it make stick in your ceiling.....). If it works, don't mess with it or the cover. If you want to make certain it is properly lubricated and free of cosmoline then use a spray cleaner, on accounta ya don't wanna mess with that dang firing pin cover...................
If you want a new set of springs for the gunsmith to install you can purchase them from Wolff Springs in Ardmor, PA - they are on the web.
Most effective ammo for those older mil-spec pieces is straight ball ammo - either 115 or 124 gn ball. There is lots of mil-surp available and extra magazines don't cost much, so you can really have a ball with those oldies. Hope this helps. Mikey.