I was wondering if anyone could help me with a species of tree that
flowers from mid-October?

I doubt that it would be a native species, but my neighbour had one in
his garden for a short period. During late October it suddenly
flowered, and attracted Red Admiral butterflies in quantity on mild,
sunny days. As a butterfly enthusiast this was an unexpected bonus,
that is until one February day the following spring a man with a
chain-saw arrived and cut the entire tree down.

Had I have known this was planned, I could have asked to take a couple
of cuttings and tried to propogate them for my own garden. The
neighbour is not a gardener and therefore has no idea what species of
tree it was, and it was there when he moved in, so he did not plant it.

Sadly, I have no details except that it was about 12-15 ft tall by its
demise, and seemed to grow relatively slowly, plus it had dark-ish waxy
leaves.

A very inadequate description, I'm afraid, but can anyone provide any clues?