Congratulations! As for your interview, I would also suggest trying to show that sure you have a stutter, but you don't let that stop you from doing difficult things, like job interviews. They can only imagine what other kinds of bravery you're capable of! They have talked to you on the phone and decided that you said things they liked (we must not forget people also listen to WHAT we say), so just keep doing what you're doing and try to be you as much as you can!