Every Glock I ever shot needed rear sights bumped to the right a little bit to center point of aim...or is it me jerkin', flinchin' and pullin'? All after 34 years of shooting? Anyone else have to?

It sounds like it is the shape of the backstrap causeing you to take a different grip on the gun then you would get on another style pistol.

I would agree with the above.

Somewhat similar situation has happened with me lately.  I have all glock pistols and have been carrying/shooting a G17 with the new style frame for the last 2 years.  I pull out one of my older G17's and go shoot it and the poi is to the left (rear sight needs to go to the right).  I know damn well that all of my sights were parfect for me previously.  The ONLY thing I can think of is that I am gripping the pistol differently because I have grown accustomed to the new style frame.  My $.02

Tate