Kopfdorfer is correct, put a 12 pounder/75mm or a 88mm gun on the bow plus a couple of 20mm, amidships and/or stern, the bigger one could play a very good HMS Naval Trawler or a VP Boot ( the German armed Trawler ) for Coastal/Harbour/Fishing Fleets protection, and a huge lot of attack missions on the Channel/Baltic/Mediterranean/Pacific theaters.
Great work, great idea.
Thanks Archie.