Is "delayed appositive" the correct term for this?

Well, yes, I suppose you could call it a "delayed" appositive, but why would you want to put the supplementary (non-integrated) appositive NP "a real brute of a man" so far away from its anchor "the hunter" when it appears (wrongly of course) that there is another possible candidate for the job, i.e. "the bear" in the vicinity? Just for a moment, the reader is likely to associate the NP "real brute of a man" with the adjacent NP "the bear", though a second look immediately dispels that possibility of course. For that reason, it's probably best avoided.

Most supplementary (non-integrated) appositives are adjacent to their NP anchor, but sometimes they can be separated:

I met a friend of yours at the party last night - Emma Carlisle.

But look what happens when you insert another possible (but incorrect) anchor:

"I met a friend of yours at the party last night with Kim Anderson - Emma Carlise". You have to do a quick double-take to establish whether the anchor is "Kim Anderson" (wrong) or "a friend of yours" (correct). Again, it's best avoided.

Incidentally, you can't normally separate an integrated appositive from the noun it modifies:

"She sang in the opera 'Carmen' at the Royal Opera House in Covent Garden" is fine, but not "She sang in the opera at the Royal Opera House in Covent Garden, 'Carmen'".

Dislocation is a different kind of construction which has a constituent (usually an NP) located to the left or right of the main part of the clause which is anaphorically linked to a personal pronoun within the main part of the clause itself:

(1) "Her parents seem pretty uncaring". (basic non-dislocated)

(2) "Her parents, they seem pretty uncaring". (left dislocation)

(3) "They seem pretty uncaring, her parents". (right dislocation)

In (2) and (3) the subject of the non-dislocated version (1), "her parents", stands outside the main part of the clause, to the left and right respectively, and the linked pronoun "they" occupies the place filled by "her parents" in the non-dislocated version.

Superficially, dislocated constructions and appositives look quite similar, but the crucial difference is that with appositives there is no personal pronoun in the main part of the clause that is linked to an external NP. Now look back at your example:

"The hunter was trying to fight the bear, a real brute of a man".

There's no anaphorically linked pronoun here, the NP "a real brute of a man" is simply an appositive of "the hunter". To change it into to a dislocated construction, you'd have to re-cast it:

"The hunter, a real brute of a man, he was trying to fight the bear".

I hope that all makes sense!