named

In 1926, an English gentleman named Henry Fowler published a book on “good” English.
Does the past participle “named” here is a short for “who was named”?
If so, how about the case the gentleman chose his name himself?

Qn No. 1. YES.
Qn No. 2. In 1926 an English gentleman who assumed the name of Henry Fowler published a book on “Good English”.

Thank you, T_H_Lawrence!

T_H_Lawrence,
Is it not correct? : ‘In 1926, an English gentleman by name Henry Fowler published a book on “good English”.’

YES. It’s also correct.

However, “In 1926 an English gentleman, Henry Fowler by name, published a book on Good English” will, perhaps, be better in structure.

The sentence in #4 requires a change in punctuation:
In 1926, an English gentleman, by name, Henry Fowler, published a book on good English.

To avoid all the commas, use the alternative in #5
In 1926 an English gentleman, Henry Fowler by name, published a book on good English.

Note that as you are not actually providing the title of the book, but rather the topic, ‘good’ should not be capitalised.

In 1926 an English gentleman, Henry Fowler by name, published a book [color=red]on “Good English”.

Yes, it should be a book on good English or a book “Good English” or a book, titled Good English.

I would say:
… a book on good English
or
… a book, “Good English” (a colon could also be used)
or
… a book, entitled "Good English".

Thanks for pointing out the punctuational nuance involved. However, if we use a colon instead of a comma, are the inverted commas necessary for Good English?

Though ‘titled’ is traditionally used as an adjective in relation to the titles conferred, it is also found used in the sense of ‘entitled’ by many, who are educated. Doesn’t modern usage admit of it as a verb (participle)?

If a colon is used in the first example, the inverted commas are not necessary.

Modern English allows many things, some of which I approve and some of which I dislike/ As titled = a person who has a title,
I’d prefer ‘entitled’.