That's great stuff, MGMike. Thanks for sharing your expertise and resources with the forum. This will no doubt help the next person who experiences something similar.
I personally prefer the both-eyes-open, big picture, point/aim method for the Walther pistols and generally pay little attention to the sights, be it with the PP, the PPK/S, the P38, the P1, the P5, the 88C, or the P99, all of which are regular range visitors. I couldn't currently tell you whether the sights on any of my pistols are on-target or off-, but I shoot well enough with all of them.