Great, thanks for the replies everyone. Something to work on now anyway.
In terms of the commercial operation of these machines, has anybody got an opinion in the practicality of carrying freight/pax vs operating costs in comparison to the likes of a Chief or 402? The dry hire rate we have negotiated still seems expensive to me vs the useful load, but perhaps clients prefer/require/enjoy the extra speed?
Back in the day, they used to use them for freight/bank runs out of YSBK. Even Airtex used them for that (PWY and IGN).
I don't know the specifics of what it cost, but it has been done.