Any one ever done this? Working on a side job, homeowner wants a Murphy door, looks like a built in book case, but needs to open up, so he can stash his valuables behind it, guns, valuables, etc. Seen a few videos on it, looking for do and don't ideas, I want it to look as flawless as possible, ideas? Thoughts?

I friend had a “secret” room for his coin collections and the door looked like storage shelves. One thing he told me was that he had to reinforce it to prevent sagging. I think he used a continuous rod instead of hinges to help with support 

I have done one in the past and the are pretty straightforward. A large full length piano hinge is the best option. You have to work out the mounding pretty carefully on either side before you start building it. The one we did was 12” deep so the diagonal measurement was quite a bit larger than the measurement of the face so the molding on the sides had to be fairly wide. 
Paul

use a wheel