I usually carry a PPK on the ankle as a BUG.
Bear in mind that the PPK is the smallest of the Walther PP series pistols, which means your fifth finger will likely be off the grip and dangle. But if you simply curl your loose finger under the grip you get a good purchase and shooting should be very accurate.
I have made no modifications (save white paint on the sights) and have never suffered slide cuts from any PPK, despite large hands.
Congratulations on a fine acquistion.
For 20 years the sea was my home, always recall the sun going down, and my trusty friend, a 1911 pistol, strapped to my side.