Who is B. L.?

Junior Library, Oriel College
(formerly the chapel of St Mary's Hall)

Wondering if Melville's mysterious "B. L." in the first book of Clarel (Canto 41, On the Wall) could be modeled after some real historical person, as The Dominican is based on Lacordaire.

Some clues and considerations regarding the person twice-named B. L.:

•  Englishman, young and good-looking ("fair")
• writes poetry . . . regular poet, or author of only fugitive verses?
• associated with Matthew Arnold. "Faith's gathering night" captures theme and spirit of Arnold's poem Dover Beach, confrontation at night with receding Sea of Faith and now pointless contest between "ignorant armies." From his study of Melville's marginalia Walter E. Bezanson judged:

“It was Arnold’s despondencies, his acute sense of the modern plight, that attracted Melville most.” --“Melville's Reading of Arnold's Poetry.” PMLA 69 (1954): 391

• Pilgrim to Jerusalem as a young man (unless that part is invented?).
• Studied at St Mary Hall, Oxford and thus connected to Oriel College, home of
  Oxford Movement.
• Complexly disaffected as verses and marginalia reveal; critical of Anglican rites and revolutionary politics. Hence convert or prospective convert to Catholicism, like John Henry Newman. Blessed John Henry Newman. BL, Bl. for Blessed? 
• If not based on any one individual, why these particular initials, "B. L."? Echo of Bartleby? Billy? Bulwer-Lytton?

From Clarel, book 1: Jerusalem, canto 41 (On the Wall):

He read: obscurely thus it ran :—

'For me who never loved the stride,
Triumph and taunt that shame the winning side—
Toward Him over whom, in expectation's glow,
Elate the advance of rabble-banners gleam—
Turned from a world that dare renounce Him so,
My unweaned thoughts in steadfast trade-wind stream,
If Atheists and Vitriolists of doom
Faith's gathering night with rockets red illume—
So much the more in pathos I adore
The low lamps nickering in Syria's Tomb.'—

'What strain is this ?—But, here, in blur, —
"After return from Sepulchre:

B. L." '—On the ensuing day
He plied the host with question free:
Who answered him, 'A pilgrim—nay,
How to remember! English, though—
A fair young Englishman. But stay ':
And after absence brief he slow
With volumes came in hand: 'These, look—
He left behind by chance.'—One book,
With portrait of a mitred man,
Treated of High Church Anglican,
Confession, fast, saint-day—deplored
That rubric old was not restored.
But under Finis there was writ
A comment that made grief of it. 

The second work hath other cheer—
Started from Strauss, disdained Renan—
By striding paces up to Pan;
Nor rested, but the goat-god here
Capped with the red cap in the twist
Of Proudhon and the Communist.
But random jottings in the marge
Disclosed some reader of the text
Whose fervid comments did discharge
More dole than e'en dissent. Annexed,
In either book was penciled small:
"B.L.: Oxford: St. Mary's Hall."

  Such proved these volumes—such, as scanned
By Clarel, wishful to command
Some hint that might supply a clew
Better enabling to construe
The lines their owner left on wall. --Clarel, Hendricks House ed.