An easy way to see "British" planes would be to add the current SH4 Brewster Buffalo model to Australia, Britain, Netherlands and New Zealand. I guess new skins would be required, but one could get away with two skins: one for the Commonwealth nations and one for the Netherlands.
Likewise, assuming it's in SH4 (I no longer have it installed), one could add the Catalina to the Commonwealth nations.
One could also add the Hurricane to the Netherlands.
Heck, if one had the inclination, I'm sure they could very easily correctly reflect the airbase movements of the British, Dutch and Australians during the war. The British and Dutch because they "disappear" after about six months of the Pacific war beginning, and Australia because once you plonk them in one spot, they tended to stay.
American airbase movements may be a bigger task though.
I'm sure it's just a matter of time before someone goes through and gives the roster and airbases a thorough overhaul.