Original 1951 target grips had no cutout for speedloaders,
by 1955 they had a small "football" shaped cutout that got larger by the 60's, in the late 70's they changed to the "Speedloader" cutout style like these:
later versions do not have the metal washers inside just wood.
Current optional wood grips are from an aftermarket supplier (Hogue or Herret?) and have a cutout similar to the ones below on SS gun,
I believe the blued gun below is wearing Ahrends retros sans medalions.
They also come with a stamped checkering as well and have a retro style diamond like the ones below