Hi, Wing_Z!
The airfiles of the planes included are tweaked, so they won't show up in the aircraft selection menu.
The Twin Otters, Electras and HS.748 are dedicated AI models, so flying them wouldn't make any sense.
The Dash7 (Air Tindi and Canadian Forces) textures are the same as I did on Milton's flyable DHC-7, but they are wrapped around an AI model.
Buffalo's C-46 Commandos are done on Mike Stone's model. You'd better take the ones I made for the Guzman Commando.
First Air's Hercules and the Buffalo Canso are also Mike Stone's models, you may copy these textures to the fully functional version the usual way.
The two Buffalo Dakotas are textures by Mike Wilson, added as a whole AI aircraft for your convenience. Copying them to the stock DC-3 makes them flyable as well.
Cheers,
Markus.