Yes, factory engraved - back before the days of laser engravings and CNC engraving. These are very collectible and not something i would buy and shoot. If it looks to be unfired then definitely don't shoot it.What you have there is a very nice, hand engraved 1973 manufactured PPK/s. It was imported by Interarms. The 22LR cal is rare in that there weren't in high demand so manufacturing was in low numbers not to mention engraved ones. They came in 3 finishes Gold, Nickel and Blue. Value would be difficult to place but the best way is to go to gun broker and look at ended auctions to see what they sold for. Very nice gun.
I have one in .380 made in 1974, in the matching box with target etc, but it has chrome finish (not nickel - check the 1974-75 Interarms catalog you doubters) and I'd put mine valued about $4,000+ based off of several 2-3 year old actual "sold" pistol data.
There is one or two gold plated 22LR's like yours on GBroker that are asking $5K and up. "Asking" - not selling/sold. Either way if you got into this rightly its a slam dunk investment to beat inflation and something you can enjoy - but if you want a shooter 22LR the new ones are super reliable and low cost so pick one of those up too.