The main issue with building a star destroyer (1:1 scale or otherwise) is that the two most iconic features, the raised bridge and wedge design, make it difficult to build in a 2D space. If you build the craft from the side view so you can easily recognize the bridge, you will end up with a small triangle with a block sticking out of it. If you build it from a top-down view so you can easily see the wedge design, you end up with a giant triangle. Either way, you will have to do some very specific detailing to create the illusion that there is more that you can’t see, or you will end up with something that only looks like a star destroyer if you’re told it is.