OK, the "grade" is stamped on the water table. Both the "H" and the "E" are implied and not stamped there because you know by looking at the gun, if it has hammer then no "H" and if it has "Extractors" then no "E" either.
Have you looked at the "Parker Identification" link found on the left side of the main web page at
www.parkerguns.org? When you look on those pages you need to know that the pictures will enlarge for you when you mouse click on them.
Check out the other links found on the main page too, they should answer most of your questions.