13b20,
There are several good books with pictures - try the Detail in Scale series, or the Squadron series.
Your gear doors probably don't fit because because as the gears were never intended to be presented wheels up on the model, the manufacturer has probably run a little "loose and fast" with the dimensions of the separate gear door pieces and didn't get them right.
In reality, the gear leg length of any wheel-down P-47 is longer that the length of wheel well itself - this was done to accommodate the huge prop the plane needed and there wasn't enough space in the airframe to extend the wells to suit. On the full sized a/c, upon retraction, the gear leg hydraulics "de-pressurised", forcing the wheel up towards the gear leg hinge, effectively shortening the free length between the hinge centreline and the wheel hub centreline, allowing the now shortened gear leg to fit into the well. Clever.
There are also heaps of other websites around with lots of photos - just go to yahoo, altavista, google (or your favorite search engine) and search for "P-47", "Republic P-47", "P-47D", "Thunderbolt", "P-47 Thunderbolt" etc etc etc.
You're bound to find heaps of websites with images you can look at.
Cheers,
LeeTree