Default [Q] Live Demo Unit

I happened to get a Samsung Galaxy S4 Live Demo Unit and yes, I know, there are a lot of threads regarding this and the final answer is that it can't be transformed in a 'real' phone but mine is a bit different. If I take the back cover off, there are no 'DEMO' stickers and under the battery it says 'GT-I9505', without 'X'. It is possible to be an actual S4 but just have the Live Demo Unit ROM?