I’m late to the thread, sounds like you’ve gotten what you need. I typically dress nicely for an interview, in a manner which conveys that getting the job is important to me. I don’t think you should dress like the prospective employers do, because you’re not “one of them” yet. Wash your face, comb your hair, and wear a coat and tie. It shows respect, and seriousness about getting the job (which may foretell how you can be expected to perform at the job). Good luck!