^^ Frodo, this is really amazing
Excellent choice of screen captures. I think you've got all the right expressions and nearly perfect lighting. Uhura probably needs a little saturation and contrast management, but Kirk looks good to me.
As for sources, I'm betting Kirk and McCoy are from "Shore Leave". Scotty, Sulu, and Uhura definitely look like early 1st season ("Where No Man Has Gone Before, "The Man Trap"). Yeah for Chekov, we'll have to wait for Season 2 to come out in HD. I wonder if you might be able to use a filter to compensate. There is an image processor that can take multiple images and combine them together for enhanced clarity. Maybe you can do that by using screen captures from several frames in immediate succession?
Either that or move Sulu into the foreground and put Chekov in the rear. They're of the same rank and command color.