In Zametki perevodchika II ("A Translator's Notes," Part Two) VN makes fun of Brodsky ("Alas, poor Brodsky!" etc.), but he also points out the mistakes in, say, H. Dupont's French version (1847) of Pushkin's Eugene Onegin:

(According to Brodsky, Onegin's bolivar points at certain public opinions of its owner who sympathizes with the struggle for independence of a small nation in South America…)”

Jansy Mello:  Alexey mentioned Onegin's "bolivar" and I was surprised by the term because I'd never heard about a "bolivar" headwear until then (I had seen pictures of "bowler hats" only).

A bit of investigative work led me to an interesting information in

http://blogdaboitempo.com.br/2014/04/22/cultura-inutil-bolivar-nao-perdeu-tempo/

where the author mentions the Brazilian gauchos, who are often depicted in typically large pantaloons ("bombacha") and the belief that such innovative fashion was stimulated by English traders at the time of the Crimean war (1853-1856). These comfortable pants, favored by the Turks, were mainly produced in England and now, unable to export them to their usual costumers because of the war, the merchants established a new market for them in South America, not only by shipping "bombachas" but, also, bowler hats now worn by the Bolivian "cholas".

I wonder if the word “bolivar” (for a certain kind of top hat) was originally employed by V.Nabokov himself in EO or if it is still in use.  

In the NY Times archives, according to John Leonard (Nov.2003) Pushkin was“… of course, short -- a ''small, swarthy, apelike poet,'' 5-foot-6, with pale blue eyes, unsightly side whiskers and clawlike fingernails, sometimes to be seen wearing a black frock coat and silk top hat like Bolivar's, sometimes with a fez and Turkish pantaloons -- and a surprising snob, boasting that his father's boyar side of the family went back 600 years. (On his mother's side, notoriously, there was that ''blackamoor'' great-grandfather from Cameroon, purchased in Constantinople's slave market as a gift for Peter the Great, who grew up to marry a Swede and become a general.) None of which interfered with Aleksandr's inordinate fondness for smoked sturgeon, Rossini operas and women with small feet. ''In such cases,'' he confided to a friend, ''I usually write elegies, as another has wet dreams. http://www.nytimes.com/2003/11/16/books/review/16LEONART.html

In Nabokov’s wording, in his EO commentary- One XLVIII- p.177 (Princeton Bollingen ed) we read: “…he is a shortish man wearing a Bolivar top hat([…]), the tapering pantaloons of the times, and an hourglass-shaped, long=skirted frock coat with two back-waist buttons. He is leaning at ease with his left elbow on the parapet…”