The new parts have arrived, including prop and prop shaft, rudder, motor, coupling, etc. Had to fabricate a 'p frame' from scratch out of 8mm brass strip. That was fun, but it came out ok - first trial fit of all the bits:

Since then, lots of filling and sanding to close up numerous gaps between the various panels. Also re-made the back of the seating area so that there's now a hatch for accessing the rudder and its servo. Pics next time.