Thank's Bob, I can read the same in 1910 catalog. I believe magazine page too small to show all Ideal grades produced at the time (probably shown best sellers). But I saw very high grade Ideal and believe it was grade 9, don't remember letters.

Satinsky in his book in 1926 described allmost all grades shown in 1910 cathalog and said highest grade Ideals were worth F6,000!
Also he mentioned grades 14 E/PF, 15/ECA and 16/EPA. Ideal's were most popular French gun in Russia according to him.
Interesting he devoted to Ideal allmost one page and said just few words about Darne

You can read Satinsky about French guns here (with translator)
http://www.huntclub.ru/Books/Satinsky/5_french.htm

Geno.