Ok, I think we've answered cornishman's question to the best of our abilities...or something like that anyway.
This thread's gone so far off topic that I think I'm going to put it to bed.
If the OP or anyone else has anything to add, let me know and I'll re-open it, but as it stands it's not serving as anything but an embarrassment. Thanks to the folks that gave informative replies.
Closed.