Does anyone know how to identify HRA and IHC Buttplates??

[Orlando]

I have been trying to do some research lately on the manufacture of Garand buttplates but havent come up with much
Does anyone really know how to identify HRA and IHC buttplates?
Was there more than one manufacture of IHC and HRA buttplates?
Take a look at these and tell me what you think
Disreagrd #3 ,I know its is Post War SA
http://i47.photobucket.com/albums/f197/Garandlover/Buttplates/Picture447-1.jpg
http://i47.photobucket.com/albums/f197/Garandlover/Buttplates/Picture451-1.jpg
http://i47.photobucket.com/albums/f197/Garandlover/Buttplates/Picture453-1.jpg

[KnickKnack]

Do you have Larry Babcock's book? According to what I'm seeing in his pictures, your #6 may be an HRA or WRA. The HRA's have no partial rows of dimples around the screw holes. The WRA buttplate he shows has a faint ridge next to the dimples around the screw holes and is stamped S2 on the inside. He doesn't show any IHC's.

[Orlando]

None of them are WRA, They are all Post War