Vimeo provided this summary of the film:
This is a short film showing the process of the detail paint work on the conservation of the original U.S.S. Enterprise miniature, used in all 79 episodes of the original Star Trek television series. The detail paint work was done between the 11th and the 23rd of April 2016 at the Smithsonian National Air and Space Museum’s Steven F. Udvar-Hazy Center in Chantilly, Virginia. The model is now on display in the Boeing Milestones of Flight Hall at the National Air and Space Museum in Washington D.C.
If you watched the recent film Star Trek Beyond you might remember a similar scene at the end of the film. However, I believe that the repair process was a little more elaborate and on a larger scale (in the movie, at least).