I have a 1997 400DA; I am guessing they have the same TV/VCR set up. The opening just above my refrigerator is basically 15” wide by 16.5” to 17.7” high. It’s not a true rectangle. I bet your TV cabinet is also arched at the top in order to accommodate the shape of the TV. Another thing to consider is, at least on my boat, there is a decorative bolster board that runs along the top of the refrigerator cabinet; just in front of the opening of the TV cabinet opening. I could not take the TV out of the cabinet with removing that piece. I considered building a storage space with a door when I remodeled my boat but elected instead to install an oven in that space. Bottom line; its best you put eyes on the project before making your plans.