Lovely, it’s a very nice model. I’ve looked at the Insect (eg HMS Cockchafer) and Fly Class (HMS Blackfly?) gunboats before. But the former would be huge at 15mm.
These were designed for operations on the Danube, actually used in Mesopotamia and later on the Yangtze.
Tim from Gomi Designs. 15mm Vietnam riverine. www.gomidesigns.co.uk