Evening All,
Thanks Zac for the encouraging comment - much appreciated.
The lower wing half from which I unintentionally removed the non-existent aileron has been totally replaced as I could not make a decent repair: the two sections just would not align properly so I took the easy route and started again. I drilled holes in the centre section and ends of the upper wing halves and inserted brass pins so that when the parts were joined I could get the correct dihedral and still have a strong joint:

The wing sections were secured with super-glue for the brass pins and cement for the plastic: the wings were jigged with scrap plastic to ensure the correct angle of dihedral:

The joints were filled and sanded smooth so now I have usable wing sections:

I have still to shape and fit the ailerons to the upper wing - holes will be drilled and brass pins used again to strengthen the joints when I do fit them.
I have been working on the upper fuselage section that held the cockpit openings. This section had flat sides and top which I decided to mould. I made a male former from basswood and a female from plywood:

My initial attempts to make a moulding failed for two reasons: first the male mould was slightly too small so that the new part did not fit on to the fuselage without leaving gaps which were too conspicuous to hide. I made a completely new male mould and tried several times before I realised that instead of using 30 thou card I needed something thicker as the mould was drawing out the plastic and still leaving gaps. When I used 60 thou card and enlarged the female mould slightly the problem was solved:

Holes were cut and shaped for the pilot's and navigator's cockpits:

and the part tested on the fuselage:

When it is properly cut to size and sanded it will make a good fit. Having placed the new part on to the fuselage it is clear that very little of the interior will be visible so I have made two seats and will add very few extra details, except seat belts and possibly a control column:

The seats were made from plastic sheet and were based on photographs of aircraft seats from the period: I have no specific details of what they were really like and as they will hardly be seen, it does not matter too much.
The floats were shaped from basswood following a simple and straightforward method which I use for all of the parts which I shape from wood or laminated plastic. I started by cutting two pieces from a larger block of basswood which were slightly longer and wider than the finished floats. I marked one of the blocks with lines 1 cm apart so that I could transfer the plan of the float to the top surface, and the side elevation to the sides:

I cut much of the excess wood from the bottom of the block to leave the side elevation visible: the upper surface of the block will be the top of the finished float:

A saw-cut was made where the float step would be and the bottom of the float was shaped with a wood file. When I was close to making the step on the underside of the float I deliberately removed wood from the rear of the step so that I could file the rear of the float flat without taking off wood from the front end:

I could draw lines across the flat bottom of the float by using the lines on the side as guides. Now it was possible to draw the plan of the float on the bottom surface:

That was necessary because the sides of the block had to be filed away to get the correct width of the float. Before filing started much of the excess wood at the front and rear ends had been removed with a saw:

The bottom of the floats were shaped like the bow of a speedboat at the front end, but were flat surfaces on either side of a keel in the centre and rear. The keel line was drawn along the centre of the underside of the float, and lines were drawn on the sides of the block to represent the edges of the float sides: the keel line and lines on the lower sides of the floats were used to guide the filing of the flat undersides of the float.

I now had a block of wood with flat surfaces. To achieve the concave curve at the front end of the floats I used a half-round file, and glasspaper wrapped around a round file to gently and slowly remove the wood to the desired shape. A centre line was drawn on the upper surface before the curved upper sides of the float were shaped with a file. I used card templates to ensure that the correct shape was made.

The upper float in the image shows the curved upper surface, and the lower float the concave nose, flat rear and step on the underside.
Thanks for looking.
Stephen.