I don't know what you are asking, If I read your post right, you are questioning if the High Power dimensions listed in the link are correct.
The 200 & 300 yard targets' scoring rings are the same size. For the 300 yard target the "8" ring is black. This was changed in the late 70s to make the "black" the same size, relatively, on your front sight. At the same time they added black to the "7" ring on the 600 yard target. Again making it the same size relative (almost) to your front sight.
When the change came about many said it was do to High Power Shooters getting old, and their eyes were going south. I don't know if that reasoning is true or not, but at the same time they changed the times for the Rapid Fire stages. It use to be, for setting, 50 seconds for gas guns and 60 seconds for bolt guns. For prone rapid it was 60 & 70 seconds respectively. Every thing was changed to 60 & 70 seconds regardless of gun.
Also I believe this was the time the CMP (then DCM) changed the rules for LEG or EIC matches. It use to be that is such matches you couldn't use a ground cloth (mat) in prone and you had to load from the person as oppose to laying the second mag. on the ground.
Anyway, to answer your question, the scoring rings dimensions listed in your link are correct.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071