Evening All,
Many thanks to all who have left encouraging comments: I really appreciate them all.
I have done some more construction work and painted the bulk of the model and it is beginning to look like what you see in the photos. I completed the horizontal tail unit by cutting and inserting between the rear fuselages a piece of 30 thou card with Evergreen strip (10 x 20 thou) ribs. I also added the small units on the outer sides of the fuselage plus the tail bracing, and then the two rods which were set between the forward parts of the fuselages: I assume that these were for the engine controls on the starboard side (the pilot sat on the port side).
Painting followed - mainly acrylics for the upper and lower surfaces but Humbrol enamel white for the floats because I have some left from the past and I find that it gives a better coverage than the acrylic paint. The struts were Revell SM 382 which is another enamel - I just like the soft brown to represent the pine of the struts. The cockades were home printed and the serial came form an old set of RNAS/RFC numerals from Pegasus. The rudder stripes were painted:



The white dots on the upper surfaces are holes for the struts. To put the top wing in place I used a procedure which I have found from experience is most suitable for multi-bay biplanes. I put some of the cabane struts into the lower wing - in this case the pair on the inner side of each fuselage, and the outer pairs of main wing struts. I used ordinary styrene cement and placed the inner struts against the fuselage sides first, then quickly added the two outer pairs and lowered the top wing. I had put drops of cement into the respective holes in the top wing. I was lucky because three of the fuselage struts fitted exactly and the fourth only need a minor adjustment. The outer struts were a little more fiddly but still went into place quickly. The whole assembly was jigged with paint pots to keep it square while it dried out overnight. The result was what I desired:


This structure was quite robust when dry and allowed me to put in the remaining struts, one at a time, without problems. After these had been put into place I again left the assembly for a couple of hours to set properly before I added the kingposts on the outer parts of the top wing:



The model is now ready to add the floats and that will be the next stage.
Thanks for looking.
Stephen.