Salve,
I don't know a great deal about this, but I do know a little. The first significant archaeological work was by Schliemann in the early 20th century, and he found evidence of a Troy from the 13th century BCE.
There is also evidence that a sack of Troy was carried out by the Greeks, in fact there were several - in one of them, an earthquake brought down the walls and allowed the Greeks in, although I'm not sure if this is the one described by Homer. One theory I have heard, though not in much depth, suggests that the horse was a statue left by the Greeks in tribute to Poseidon (Whose special animal it was) who was the God in charge of earthquakes.
As for the characters - they are related to characters who are believed to be mythical, eg Achilles son of Peleus, Ajax son of Telamon, Odysseus, bastard son of Sisyphos (possibly) which doesn't lend their existence credibility. However, if I remember correctly, Thebes was sacked by some Greek army or other - possiby the Argives - and Diomedes was said to have razed Thebes.
And the nature of Mykenai's dominance of Greece after the fall of Crete meant that a coalition such as the one that was meant to have ventured to Troy is entirely feasible.
Hmmph. In among that rambling you might find something useful, it's all skimmed off the top of my head, so don't sue me over any errors.
Bene vale,
Marcus Scribonius Curio Britannicus.