New appoach through reflection.

By looking at the object returned by downloadManager.getTorrent(), this object has a delegate which is a TOTorrentDeserialiseImpl.
I've managed to make that delegate object public though reflection, and I've made my FWTorrent class extend TOTorrentDeserialiseImpl, so that I can downcast the TOTorrentDeserialiseImpl into my sub class which exposes the methods to manipulate the info hash.

I'm however getting class cast exceptions at the moment.