I don't know if I'd call it 'Just another PPK' - PPKs are fantastic pistols (IMHO) when compared to today's poly/aluminum crop. I cannot see all of the markings to state positively, but from what I see is a Post-War civilian Walther. Looks a tad neglected from the pitting. I'd bet a good cleaning and oiling is in order.
If this IS a 'Post War' civilian model, refinishing by a GOOD GUNSMITH might be in order. If it were a more collectable WW2 German military piece it would be best left as-is, but while the post war civilian models aren't as collectable, they are still very nice pistols.
Your pistol is a 7.65mm (.32 ACP) that today is seen as sub-marginal as a stopping power defensive round. Back in the 30s, 40s and 50s they were looked upon as 'decent' in power. They did seem to 'do the job' as far as European military was concerned. Your pistol has the flat base magazine, but there are after market 'extended base' magazines that greatly improve handing and shooting of the PPK with the small grips. If you were asking for the current value, I'd guess somewhere between $400 and $500. I've been away from the shooting/collecting pack for a very long time, and I'm certain someone with more current info will be along shortly. Great post!