Wonderful model with great detail in particular the mast detail and radio aerials. A long time ago I was a National Service man in the RAF and after my initial trade training as an air wireless fitter was posted to RAF Mountbatten at Plymouth, this was in 1961. By then the marine craft service in the RAF was being greatly reduced due to its primary role in air sea rescue being taken over by helicopters the main roles then were target towing and general range duties. Mountbatten had become the maintenance unit of marine service and when I was there we had some RTTLs, and a number of smaller boats. It was an unusual RAF station in that we were both the Maintenance Unit for the service and an operational camp. I was only there for a year and was initially only involved with the normal daily activities of testing and repairing the radio gear fitted to the boats. But as in civilian life I had completed a engineering apprenticeship I was capable of producing engineering drawings, so I took up residence in the small room nominated as the drawing office with just me as its resident. The job I was given was to produce the drawings of the installation of the UHF radio in the RTTL this was to be used as the locator system in the recovery of Sonobouys. The aerial arrangement for it is the twin multi dipole system you so skillfully produced in your model. The thing that looks like a cage is the di pole for the VHF radio system which was the main comms provision for the boats.
I had a few trips on RTTL's but generally not too far. There was an original build of the RTTL that still had 3 Napier Lions as the prime movers and I set off one very fine day for a joy ride on this, but not long after getting outside of the Plymouth break water one of the engines packed up and we sadly had to come back.
I have never seen before a canopy fitted to an RAF boat and as a RTTL was capable of going quite fast I wonder if it was something a bit unofficial, done locally near the end of its service.