I have a set of repros from both Sarco and Numrich. They are several years old and may no longer be representative but I thought I would include them for discussion.
The lighter set is from Numrich and the checkering is finer than my OEM 9mm S/42 grips. The darker is from Sarco and is coarser than the S/42 grips. The Numrich measure .298" thick, the Sarco are .334". Both measurements taken in the middle excepting the locating ribs.
The Numrich is pleasant to hold and shoot. The Sarco are much thicker and the coarse checkering is almost painful. But the Sarco look much better in display.
I don't recall if either required much fitting. One annoying point on both of these is the forward top projection on the left grip - the point. It does not fully fill the cavity of the pistol above the mag button. I have noticed this on Thai and India repros as well.