Iambecomelife: I dont know if its an area your planning to include at this stage of your mod but if the Atlantic becomes an area of focus, may I suggest oyou might spend some time representing Cork on the South coast of Ireland.
http://corkshipwrecks.net/historypage.htm
Part of Great Britain then, it was a pivotal area for Atlantic operations for the Royal Navy it being that bit further west. Queesntown (now Cobh) was also a stopping point for tranatlantic liners such as the Titanic, for example. Within the scope of this mod, perhaps a representation of the US Navy subchasers stationed there could be done, or at least armed trawlers of some sort?
http://www.flickr.com/photos/33577523@N08/6785985797/
Also see this:
http://corkshipwrecks.net/Qships.htm
Unfortunately, from a modelling point of view, the old survey maps of Cork Harbour I have access to are incomplete but im sure detailed information must be published online somewhere.
Also, I found good line drawings of armed trawlers from this era (im sure you must have come accross, as i found them through a google search).
Regards and good luck - I really like the look of this mod and I admire your efforts so far.