You can hear at least some of the fragments reconstructed by Timo Virtanen through Youtube as well; type, for example, "Sibelius fragments"; these are the ones that Storgårds played with Helsinki Philharmonia a few years back. Incidentally, saying, as the notes do, that Sibelius was prevented from completing his eighth symphony due to illness looks suspicious to me. He did suffer, as we might now put it, from hand movement disorder, and some people have posthumously diagnosed it as essential tremor. But that hardly sufficed to seal the fate of the symphony. Anyway, this is grossly off topic here.