My immediate thoughts.
Dougal99 is 100% correct.
One idea would be putting the model on a standard stand, then placing this on a glass shelf. The glass shelf would allow up lighting and down lighting, depending on your mood. Glass shelf kits are easily available.
Additionally, an open backed Perspex box could then be hung separately on the wall, over the model. this distributes the weight over more of the wall.
However, as most viewing well be from slightly above, and some viewers will be small, this would not be very high up the wall. I am also thinking that case covering the model will need to be two inches, at least, wider than the beam of the model (one inch clearance either side). The case would also need to be about 2m long.
With this in mind, I would be inclined to build a floor standing, glass fronted cabinet. With the HMS Kent model centrally mounted on a glass shelf. I could then place other things on the base shelf, and the top of the cabinet can be used to display other things, like SWMBO's ornaments. That way I could not be accused of stealing the whole wall for myself.
One way to test options is to build full size mock ups, out of cardboard boxes, and packing tape. You only need side walls, top, and bottom to get a feel of how much floor/wall space your display case will actually take. If you leave the front and back open, you will be mimicking a glass fronted case. You can make the frames by folding cardboard into square or triangular tubes. These mockups could be something to play with whilst waiting for glue to dry, or in those moments when you have modelers block.
The idea of cardboard mock ups is an old cabinet makers trick I have used. The number one design mistake/sin of people new to cabinet making, is constructing pieces that are too large. Been there, done that. Mock ups avoid the problem.