Again, the C-47 was the military classification of the DC-3. Same plane. 10,000 C-47s (the
military classification of the DC-3) were built. 
Sorry, but I will be arguing semantics on this one...
C-47/53/117 was not the classification for the DC-3. The DC-3 used by the USAAF were all C-48's, C-49's, C-50's, C-51's or C-52's, depending on the airline who they were taken from and the engines installed.
While yes, the basis for the C-47/53/117 started from the original DC-3 design, from a practical and LEGAL standpoint, they are not the same plane.
The C-47 was built as a cargo plane with the rear cargo doors and a metal floor to handle the weight of the loaded cargo. The C-53/117 was a C-47 but only had the paratrooper door as they were made to haul people. All DC-3's and C-53/117's came with wooden floors. Some DC-3's had the passenger doors on the right side of the plane vs the standard left.
The military birds had a lot of differences from the DC-3. The mechanic who is working on our C-47, who worked on DC-3's in the airlines, has even been saying so. I also recently found out from the guy who is putting together the maintenance program for the FAA for our C-47 that not all C-47's could conform to civil DC-3 specs due to the differences in the planes for those certain ranges in build numbers.
C-47 IS the model designation for the plane. For all of the certificates and data plates for these planes, the model is listed as a C-47, NOT a DC-3.
This is true for many Civilian and Military aircraft of the same heritage.
For example, we also have a Piper L-21B Seneca. Civilians would call it a Piper PA-18-135 Supercub, but that is incorrect. The L-21B, which was a military version of the Super Cub, has major differences in the structure of the plane. To name one example, on the civilian plane, the wing has 16 ribs; on the L-21B, it only has 13 ribs.
Another would be the Boeing 707 and the C/KC-135. Both started out from the Boeing Dash 80 design. However, the 707's fuselage is a whole 6 inches wider than the C/KC-135.
