Help Identifying German Proof Marks

[schultzie82]

I have a Luger with a few proof marks that I need help identifying if anyone could. I have attached pictures to show the proof marks. Besides what the pictures have in them this pistol also has 8.83 stamped on the barrel as well as S/42 on the top of the pistol. I know it means Mauser was the manufacturer and it was made specifically for the German Military. Also I know the 8.83 is the ID of the bore which would be 8.83mm. Is that a .380 or 9mm? Finally what is the best way to clean this pistol without damaging it? I was going to just wipe it down with gun oil. Any help identifying the stampings on this pistol would be greatly appreciated. If you would like more or better pictures let me know. Thank you very much! Also under the two sybols on the side of the pistol is the number 63 any ideas what it means?