When did Pachmayr Presentation grips get speed loader relief cuts?

[.455_Hunter]

I have four sets of the Pachmayr Presentation grips that I have acquired used over the years for the K/L-frame square butt (size small). I just noticed today that one of them is not relieved for speed loader access. Just curious- Does anybody know when this change was made?

 

[UncleEd]

I'm guessing but the speed loader reliefs probably
occurred in the 1970s, early 1980s as the loaders
became more popular in use among police.