I recently traded for this pistol and don’t know much about it any information would be greatly appreciated

Can someone help me identify the history of my PPK? There's a series of numbers on the right side of the slide that reads: 1/59 12-120-0890. I have searched the web and even reached out to Earl. Earl basically told me he's never seen anything like this. Any help will be appreciated.

Hello all! New to the forums here! I recently picked up this post war p38. I was hoping someone could help me with the markings? All 3 serials match...frame, slide, barrel. Not sure if the "w 9.73" marking near the trigger guard is the date or not? Any help with that and other small stamps...