I picked up this book by Zvonimir Freivogel at the Croatian Maritime Museum in Split. He has written several books on Yugoslav and Austro-Hungarian naval history, some of which have been translated into English (not perfectly, but good enough). Unfortunately, however, they can be difficult to access in the UK.
|Partisan boats like this one would have 2-pdr guns or Italian 20mm Bredas mounted.
|Two torpedos struck my transport ship in a game of Cruel Seas.