In answer to Supermarine305: I can see why you might think that, but only the first 5 TF1s ever had a torpedo slung underneath and they were quickly modified to B1 standard. This was long before problems arose with the long barrelled 20 mm cannon.

My opinion is that it was for an unbuilt project of the TF where 2 larger calibre weapons would be employed in its anti-shipping role. What calibre these may have been is anyones guess. I also cannot understand why this model was made of brass. I had it from JD ‘Doug’ Oughton who was involved flying most of the torpedo trials. Perhaps the model is unique!

Thank you longshot. I had attempted to do that but since a software update on Windows 10 my ability to do things I previously could has vanished!