Here him one = himself in respect to its construction.
[§ 518]. As to the inflection of the word -self, all its compounds are substantives; inasmuch as they all take plural forms as far as certain logical limitations will allow them to do so—ourselves, yourselves, themselves.
Myself, thyself, himself, itself, and herself, are naturally singular, and under no circumstances can become plural.
Themselves is naturally plural, and under no circumstances can become singular.
Ourselves and yourselves are naturally plural; yet under certain circumstances they become singular.
a. Just as men say we for I, so may they say our for my.
b. Just as men say you for thou, so may they say your for thy.
In respect to the inflection in the way of case, there are no logical limitations whatever. There is nothing against the existence of a genitive form self's except the habit of the English language not to use one, founded on the little necessity for so doing.—Are you sure this is your own? Yes, I am sure it is my own self's. Such an expression is both logic and grammar.
When an adjective intervenes between self and its personal pronoun the construction is always in the way of government; in other words, the personal pronoun is always put in the genitive case.