Firstly I think you are confusing Ship Interiors with the maps available in the foundry.
You can not edit bridge maps in the foundry and have them show on your ship. There is simply no way to do that.
Seconly. When you are in the Customize Ship dialog box to change your ship's appearance in game please make sure that you click 'purchase' and not 'save'. That way any changes you make in that dialog box are accomplished.