Plagiarizing Napoleon's Praise in "Jimmy Rose"

In his glory days before bankruptcy, Jimmy Rose is said by the narrator of Melville's short story "Jimmy Rose" (first published in Harper's magazine, November 1855) to have plagiarized a compliment. Plagiarized in a good way, since done in praise of a hero:

"Sir," said he, in a great drawing-room in Broadway, as he extended toward General G----- a brace of pistols set with turquois. "Sir," said Jimmy with a Castilian flourish and a rosy smile, "there would have been more turquois here set, had the names of your glorious victories left room." 

Ah, Jimmy, Jimmy! Thou didst excel in compliments. But it was inwrought with thy inmost texture to be affluent in all things which give pleasure. And who shall reproach thee with borrowed wit on this occasion, though borrowed indeed it was? Plagiarize otherwise as they may, not often are the men of this world plagiarists in praise.

Melville assures us the compliment to General G (for Gaines, as in Edmund P. Gaines?) was "borrowed wit," without identifying any source.

Melville is not kidding here, the praise is plagiarized--from Napoleon.  In complimenting General G----- on the number of his victories while making a presentation of pistols, Jimmy Rose adapts the eloquence anecdotally attributed to Napoleon when doing the same thing:

He [Napoleon] presented Moreau, on one occasion, with, a magnificent pair of pistols as a cadeau. "I intended," said he, " to have got the names of your victories engraved upon them, but there was not room for them."

Quoted from "Eloquence of the Camp--Napoleon Bonaparte" in the December 1847 Dublin University Magazine, reprinted in Littell's Living Age (January 29, 1848) and the February 1848 Eclectic Magazine.

An earlier version of the same anecdote more closely matches Melville's conceit, with diamonds on Moreau's pistols described as competing for space with the desired engraving of the recipient's many martial triumphs:

ELEGANT COMPLIMENT TO MOREAU.

It was in 1796 that the directory first introduced the practice of giving arms of honour to those individuals who had distinguished themselves in the field. Buonaparte, on becoming consul, abandoned this custom, and only recurred to it once, in favour of Moreau. Soon after the winter campaign, which had been distinguished by the battle of Hohenlinden, Napoleon presented the victor with a pair of pistols richly set with brilliants, and taking them out of his hands immediately after, gave them to the minister of the interior (Lucien), with directions that the general's victories should be engraven on them. "But not all of them," he added; "for in that case there will be no room for the diamonds!"

Quoted from The Napoleon Anecdotes, ed. W. H. Ireland, vol. 3 (Boston, 1830), 179,

Battle of Hohenlinden