It looks amazing! Great job!

Also I can give you a tip for editing out the rest of the map outside around your castle and I have did this trick with my map that I put on the forums for a MM map called "Castle In The Sky". What I did was use the /fill command. Using that command you go to where you wanted to start and do /spawnpoint to see your x,y,z coordinates ( your x coordinate should be 3 if you have a flat world), then when you are done with that you go diagonally to how many blocks you want away from my map ( I did to where no one can see the flat grass area to make it look like it's in the sky). When you have the right amount of blocks you want do another /spawnpoint to see the other x,y,z coordinates ( the second spawn point x should be 0) . After you have both of the spawn points use the /fill command and put air after you coordinates.
Example: /fill 12 3 89 24 0 37 air
I hope this helped! ^-^
