Looks familiar, but I can't place where I saw it.
The letters are a good example of 19th century ornate initials combined with foliage that intertwines with the letters and arabesques to form an elaborate frame. This is not hand lettering. Note the identical N. Copies for printers were produced by a process called electrotyping. Printer's specimen books circa 1900 and earlier included a section on eletrotyped intials. These initials were sold separately rather than as a font. A common practice was to produce only the most commonly used initial letters such as E and S, and ignore the rare ones such as X and Z.
These initials were not in the ATF catalog of 1897.
You mentioned "Bohemian." Perhaps a foundry like Bauer?
Some of the electrotyped initials have been collected and digitized by fontmakers such as Intellecta, Greater Albion and GLC. Unfortunately their offerings do not include these particular initials. Perhaps another fontmaker.
The image appears to be a collage of printed material from various sources.
Publishers [Dover and others] used to publish books with collections of decorative alphabets. This may have been the source used by the artist. If you know who the artist is, you could ask. Or you could do some research at a library with a collection of such books.
If you are lucky, one of our typophiles may have some info on these initials.
Don